00  K 


URNERS 


.   HI] 


HAN  D-BO  OK 


FOB 


CHAECOAL  BUENEES 


G.    SVEDELIUS. 

TRANSLATED    FROM    THE   SWEDISH 

BY 

n.  B.  ANDERSON,  A.M., 

OF  SCANDINAVIAN  LANGUAGES   IN  THE    UNIVERSITY  OF  WISCONSIN. 


EDITED    WITH    NOTES 

BY 

W.  J.  Lv  NICODEMTTS,  A.M.,  C.E., 

fROFESSOB   OF   ClVlI.  ENGINEERING  IN  THE   UNIVERSITY   OF   WISCONSIN. 


With   Twenty -three  'Wood  Engravings. 


NEW    YOKK: 
JOHN    WILEY    &     SON, 

15    ASTOK   PLAGE, 

1875. 


rp^a/ 


Entered  according  to  Act  of  Congress,  in  the  year  1875,  by 

W.  J.  L.  NICODEMUS, 
In  the  Office  of  the  Librarian  of  Congress  at  Washington. 


JOHN  F.  TROW  &  SON, 

PRINTERS  AND  ELECTROTYPKRS, 

205-213  East  izt/t  St., 

NEW   YUKKi 


OL0 

GENERAL  DANIEL  TYLER, 

TJ.     S. 


EMINENT    AS   A    SOLDIER  AND    SCHOLAR,    TO   WHOM  THE  READERS  ARE 
INDEBTED  FOR  ITS  PUBLICATION  IN  THE  ENGLISH  LANGUAGE, 

THIS    VOLUME  is  RESPECTFULLY  DEDICATED, 


390341 


PREFACE. 


THE  Government  of  Sweden  offered,  in  September, 
1862,  a  prize  of  fifteen  hundred  rix-dollars  for  the  writ- 
ing of  a  suitable  and  popular  treatise  on  the  manufac- 
ture of  charcoal,  and  the  preparation  of  peat. 

A  Committee  of  three,  representing  the  Commercial, 
Agricultural,  and  Iron  Manufacturing  interests  of  the 
country,  was  appointed  to  decide  on  the  papers  handed 
in. 

In  March,  1864,  four  treatises  had  been  presented,  but 
it  was  decided  that  none  of  these  deserved  the  prize. 

In  June,  1867,  seven  treatises  had  been  handed  in. 
Of  these  the  Committee  decided  that  no  one  deserved 
the  prize,  but  concluded  to  give  to  the  authors  of  the  best 
two  productions  eight  hundred  and  fifty  rix-dollars, 
upon  condition  that  they  gave  their  productions  to  the 
Committee  to  use  as  it  deemed  proper. 

The  Committee  then  recommended  that  these  two 
treatises  be  given  to  a  third  party,  and  a  prize  of  six  hun- 
dred and  fifty  rix-dollars  be  offered  him  for  a  satisfactory 
paper  on  charcoal  making  only. 

Mr.  Svedelius  was  designated ;  he  accepted  the  ap- 
pointment, and  produced  the  present  work,  which  was 


VI  PREFACE. 

duly  approved  and  published  by  the  Government  in 
1872. 

Besides  the  manuscripts,  Mr.  Svedelius  availed  himself 
of  what  information  he  could  find  on  the  subject  from 
other  sources,  being  ably  seconded  in  his  efforts  by  the 
Committee. 

He  obtained  valuable  information  from  the  works  of 
Charles  David  Yon  Uhr,  Dr.  Thomas  Scheerer,  C.  A. 
Smith,  and  G.  A.  Molinder. 

His  work  is  probably  the  best  treatise  on  the  manu- 
facture of  charcoal  that  has  ever  been  written. 

W.  J.  L.  KICODEMUS. 
University  of  Wisconsin,  Jan.  24,  1874. 


CONTENTS. 


PAGE 

INTRODUCTION xi 

CHAPTER  I. 
WOOD. 

Its  elementary  composition 1 

The  moisture  of  wood 4 

Natural  seasoning  of  wood 6 

The  shrinkage  of  wood 8 

Wood  heated  in  a  covered  vessel 8 

Combustion  of  wood  in  the  open  air 12 

Combustion  of  wood  with  a  limited  amount  of  air 16 

CHAPTER  II. 
CHARCOAL. 

Its  general  qualities 20 

The  chemical  composition  and  moisture  of  charcoal 21 

How  charcoal  varies  in  weight  and  quality 23 

The  shrinking  of  wood  in  charring 24 

CHAPTER   III. 

THE  PROCESS  OF  MAKING  CHARCOAL. 

Various  methods  of  making  charcoal 26 

Usual  methods  of  charring  in  metiers 27 

1.  STANDING   MEILERS   OR  HEAPS   ON  HORIZONTAL   HEARTHS 

WITH   CHIMNEY   AND   COVERING. 

The  preference  of  old  hearths 29 


Vlll  CONTENTS. 

PAGE 

Choice  and  preparation  of  a  new  hearth 30 

The  care  and  improvement  of  the  hearth  after  coaling. ....  34 
The  felling,  seasoning,  and  sorting  of  wood  to  be  coaled. ...  35 
The  staking  out  of  the  hearth  ;  making  of  chimney ;  rais- 
ing of  the  wood .. 39 

Putting  on  of  the  covering 44 

Covering  the  metier  with  brushwood 46 

Covering  the  meiler  with  charcoal  dust 48 

Igniting  the  meiler 51 

The  three  principal  periods  of  coaling 57 

THE  FIRST  PERIOD   OP   COALING. 

Heat  at  the  foot  of  the  meiler 58 

Changes  in  the  upper  part  of  the  meiler 59 

Sweating  of  the  meiler 61 

The  advantage  of  heating  the  meiler  slowly. 61 

The  smoke  of  the  meiler 62 

Explosions  in  the  meiler  63 

The  shrinkage  of  the  billets 69 

Progress  of  the  fire  from  the  chimney 69 

THE   SECOND   PERIOD   OF   COALING. 

The  condition  of  the  meiler  at  the  beginning  of  the  second 

coaling  period 71 

Smoke-vents 72 

The  regular  progress  and  care  of  the  meiler 73 

Irregularities  in  the  progress  of  coaling 76 

TlIE   THIRD   PERIOD   OF   COALING. 

The  condition  of  the  meiler  at  the  beginning  of  the  third 

coaling  period 78 

The  care  of  the  meiler 79 

The  removal  of  the  meiler  and  preservation  of  the  charcoal .  -83 

The  sealing  of  the  meiler 88 

2.  THE  GERMAN  STANDING  MEILER. 

The  preparation  of  the  wood 93 


CONTENTS.  IX 

PAGE 

The  raising  and  thatching  of  the  meiler 95 

The  watching  of  the  meiler 97 

3.  THE  ITALIAN  STANDING  MEILER 100 

4.  THE  COALING  OP  SLABS  AND  OTHER  REFUSE  PROM  SAWING  104 

5.  COALING  OP  STUMPS,  ROOTS  AND  BRANCHES 106 

C.  STANDING  MEILER  ON  A  HORIZONTAL  HEARTH  WITH  A  CEN- 
TRE BLOCK 108 

The  making  and  watching  of  the  meiler 108 

The  advantages  and  disadvantages  of  this  method 110 

Suggestion  as  to  kindling  a  standing  meiler  on  a  horizontal 
hearth,  in  the  covering 114 

7.  STANDING  MEILERS  ON  SLOPING  HEARTHS. 

Introduction • 118 

The  Molinder  meiler 119 

The  Vermland  meiler 123 

8.  LYING  MEILERS. 

The  common  Swedish  lying  meiler 130 

The  hearth  and  billets 131 

Building  and  thatching  of  the  meiler 133 

The  watching  of  the  meiler 139 

Other  kinds  of  lying  meilers    147 

CHAPTER  IV. 

THE   RESULT  OP   COALING. 

Coaling  during  different  seasons  of  the  year 151 

A  comparison  of  the  different  methods  of  coaling 152 

The  size  of  the  meilers 154 

The  cubic  measurement  of  meilers 155 

Calculation  of  the  apparent  quantity  of  wood  in  a  standing 

meiler 156 

Calculation  of  the  apparent  quantity  of  wood  in  a  lying 

mdler 159 

The  charcoal  product .162 


X  CONTENTS. 

PAGE 

Closing1  remarks 163 

Table  No.  1.  The  cubic  contents  of  standing  metiers  calcu- 
lated as  cylinders 166 

Table  No.  2.  The  cubic  contents  of  standing  metiers  calcu- 
lated as  frusta  of  cones 167 

APPENDIX. 

Note  I.    Lignin 173 

Note  II.    Natural  seasoning  of  wood 175 

Note  III.     Sour  hearth 175 

Note  IV.     Last  as  a  measure 175 

Note  V.    Charring  in  ovens  and  kilns k 175 

Note  VI.     Chinese  methods  of  charring 186 

Note  VII.     Charring  in   circular  piles  as  practised  in  Ba- 
varia and  other  places 189 

Note  VIII.     Tables 201 

1.  Showing    the    percentage    composition    of    wood-char- 
coal. 

2.  Showing  the  percentage  composition  of  charcoal  prepared 
at  different  temperatures  from  wood  previously  dried  at 
150°  C. 

3.  Showing  the  nature  and  proportions  of  the  fixed  and 
volatile  matter  produced  by  the  carbonization  of  wood 
(previously  dried  at  150°  C.)  at  different  temperatures. 

4.  Showing  the  yield  of  wood-charcoal  by  carbonization 
when  the  volatile  products  are  not  allowed  to  escape,  but 
are  retained  under  pressure. 

5.  Showing    the    composition    of  wood-charcoal  made  at 
different  temperatures  under  pressure. 

6.  Showing  the  weight  of  a  cubic  metre  of  charcoal  from 
different  kinds  of  wood. 

7.  Showing  the  number  of  volumes  of  various  gases  absorbed 
by  one  volume  of  boxwood  charcoal. 

8.  Showing  tho  nature  and  quantity  of  the  gases  existing  in 
wood-charcoal. 


CONTENTS.  XI 

PAGE 

9.  Showing  the  composition  per  cent,  by  volume,  of  the 
gases  evolved  from  wood-charcoal  when  strongly  heated. 

10.  Composition  per  cent.,  by  volume,   of  the  permanent 
gases  evolved  by  carbonizing  wood  at  the  temperature  of 
boiling  mercury. 

11.  Composition  per  cent.,  by  volume,  of  the  gases  produc- 
ed by  exposing  the  volatile  products  of  the  carbonization 
of  wood  to  a  very  high  temperature. 

12.  Showing  the  amount  and  composition  of  the  matter 
evolved  by  subjecting  dry  wood-charcoal  to  a  white  heat. 

13.  Showing  the  composition  per  cent. ,  by  volume,  of  the 
gases  formed  by  passing  steam  over  incandescent  wood- 
charcoal,  and  collected  in  different  receivers. 

14.  Composition  per  cent.,  by  volume,  of  the  gases  formed 
by  passing  steam  over  wood-charcoal  at  a  red-white  heat. 

15.  Composition  per  cent.,  by  volume,  of  the  gases  formed 
by  passing  steam  over  a  single  very  small  piece  of  wood- 
charcoal,  at  a  red-white  heat. 

16.  Showing  the    relative  value  of    French  and  English 
weights  and  measures. 

Note  IX.     Charring  in  iron  retorts 216 

Note  X.     Uses  of  charcoal. .  .  216 


INTEODUCTION. 


EVER  since  the  earth  began  to  produce  plants  and 
animals,  there  has  been  a  constant  chemical  separation 
and  transposition  of  the  elements  carbon,  oxygen,  hy- 
drogen, and  nitrogen,  which,  united  in  various  ways,  make 
up  the  organic  composition  of  all  living  things.  Com- 
bustion and  decay  are  nothing  but  unlike  manifestations 
of  this  activity  of  nature.  When  the  plant  or  the  animal 
dies,  and  is  rapidly  transformed  by  a  free  access  of  air 
and  more  or  less  development  of  heat, — that  is,  if  a  com- 
plete decomposition  takes  place, — then,  by  the  assistance 
of  the  air,  all  the  organic  substances  assume  the  gaseous 
form,  and  only  the  inorganic  substances  remain,  in  the 
form  of  ashes,  burnt  bones,  etc.  These  inorganic  sub- 
stances are  everywhere  found  in  greater  or  less  quantities. 
If,  on  the  other  hand,  the  change  takes  place  slowly, 
while  the  free  admittance  of  the  air  is  more  or  less  limit- 
ed, then  only  a  part  of  the  organic  elements  escape  in  the 
form  of  gas,  and  a  number  of  solid  and  liquid  substances 

o       ^  J- 

are  formed,  which  remain,  as  it  were,  on  the  boundary 
line  between  organic  and  inorganic  bodies.  A  well- 
known  substance  of  this  kind  is  the  soil,  with  its  innumer- 
able varieties.  Other  similar  substances,  although  differ- 


XIV  INTEODUCTION. 

ing  much  in  composition  and  quality,  are  coal,  charcoal, 
and  peat,  which  are  subject  to  the  same  process  of  de- 
composition. This  decomposition  strives  to  release,  in 
the  form  of  gas,  all  oxygen,  hydrogen,  and  nitrogen,  with 
a  greater  or  smaller  portion  of  carbon,  while  the  re- 
mainder of  the  carbon  and  most  of  the  inorganic  elements 
remain  unaffected  by  the  chemical  action  referred  to. 

Besides  the  slow  process  of  making  coal,  which  takes 
place  everywhere  in  nature's  laboratory  where  remains  of 
animal  or  vegetable  life  are  found  either  in  large  masses 
or  in  scarcely  visible  quantities  imbedded  in  the  earth, 
man  has  from  time  immemorial  used  artificial  methods  by 
which,  in  a  few  days,  changes  are  produced  in  wood,  coal, 
and  other  materials  as  great  as  those  which  nature  takes 
thousands  of  years  to  produce. 

It  is  worthy  of  notice  that  all  the  various  gradations  of 
coal-bearing  substances,  from  graphite  through  anthracite, 
bituminous  coal  and  charcoal  to  the  nearly  unchanged 
wood  and  peat  which  we  find  in  the  bowels  of  the  earth, 
have  their  counterparts  in  the  charcoal  pit,  from  the 
black,  glistening,  ringing  coal,  through  the  sooty  varieties 
of  coal  without  lustre,  of  a  brownish  color  and  burning 
with  a  flame,  to  the  brownish-white  brands  ;  and  the  tar 
produced  in  the  charcoal  pit  has  its  counterparts  in  the 
petroleum  and  asphalt  of  the  earth. 

It  has  already  been  indicated  that  man  has  discovered 
how  to  produce  coal  not  only  from  fresh  animal  and  vege- 
table substances — among  which,  however,  wood  is  the  only 
substance  that  is  serviceable  for  making  charcoal  on  an 


INTRODUCTION.  XV 

extensive  scale — but  also  from  the  remains  of  organic  sub- 
stances which  have  been  more  or  less  carbonized  in 
nature ;  and  hence  we  must  distinguish  between  the  pre- 
paration of  charcoal  on  the  one  hand,  and  the  preparation 
of  peat  and  coke  on  the  other.  This  hand-book  will  take 
into  consideration  only  the  manufacture  of  charcoal,  espe- 
cially as  it  is,  or  ought  to  be,  practised  in  Sweden. 


HAND-BOOK  FOR  CHARCOAL  BURNERS. 


CHAPTER  I. 

WOOD. 

Its  Elementary  Composition. 

FOR  various  technical  purposes,  coal  prepared  from 
several  other  substances,  such  as  bone,  blood  and  flesh, 
etc.,  is  used,  but  in  the  manufacture  of  the  coal  that  we 
are  to  consider  in  this  work,  the  material  is  procured  only 
from  the  different  parts  of  the  tree ;  its  stem,  bark,  limbs, 
twigs,  and  roots.  These  differ  somewhat  in  their  chemical 
and  physical  composition  ;  but  these  differences  are  so 
insignificant  that  they  may  be  neglected,  especially  as  the 
stem  itself  constitutes  the  greatly  preponderating  material 
for  making  charcoal.  Hence,  what  is  said  about  the  stem 
may  also,  when  nothing  to  the  contrary  is  definitely  ex- 
pressed, be  considered  as  applicable  to  the  other  parts  of 
the  tree. 

The  species  of  wood  from  which  most  of  the  charcoal 
is  made  in  Sweden  are  spruce  and  pine.  Besides,  birch, 
alder  (betula  alnus),  asp  (populus  tremula),  and  even 


A 

2  HAND-BOOK    FOE   CHARCOAL    BURNERS. 

other  foliferous  trees  are  used.  Those  here  enumerated, 
as  well  as  all  other  varieties  of  trees,  consist  mainly  of 
two  essentially  different  substances,  wood  and  sap  ;  while 
the  pores  contain  more  or  less  air,  although  this  forms  no 
part  of  the  tree. 

The  wood  constitutes  the  solid  part  of  the  tree,  and 
consists  chiefly  of  vegetable  fibre,  which  is  found  in  all 
plants  without  exception,  however  different  their  forms  or 
qualities  may  be,  in  the  finest  moss  as  well  as  in  the  hardest 
and  largest  tree.  This  substance,  which  we  see  every  day 
in  its  purest  forms  in  well-bleached  linen,  in  cotton,  and 
white  paper,  is  composed,  according  to  the  best  authorities, 
of  44.4  parts  carbon,  6.2  parts  hydrogen  and  49.4  parts 
oxygen.  As  the  two  latter  elements  are  found  in  the 
same  proportion  to  each  other  in  vegetable  fibre  as  in 
water,  we  may  therefore,  in  a  certain  sense,  regard  the 
vegetable  fibre  as  consisting  of  carbon  and  water.  Through 
the  intercellular  spaces,  in  and  among  the  vegetable  fibres, 
ascends  and  descends,  as  long  as  the  plant  lives,  the  sap, 
which  is  chiefty  composed  of  water  containing  organic 
and  inorganic  substances,  partly  in  a  dissolved  and  partly 
in  a  mucilaginous  condition. 

Part  of  these  organic  substances  form  new  layers  of 
wood,  and  part,  having  the  properties  of  starch,  are  stored 
in  the  tree  during  the  winter  months,  when  the  growth  of 
the  tree  has  ceased,  for  the  next  years  development.  This 
starch  contains  the  three  elements,  carbon,  hydrogen,  and 
oxygen,  in  the  same  proportions  to  each  other  as  they  are 
found  in  the  old  fibres.  The  other  organic  elements  in 


HAND-BOOK   FOE    CHARCOAL    BURNERS.  3 

the  sap  are — or  are  transmuted  into — all  kinds  of  organic 
and  combustible  substances,  which  likewise  are  diffused 
through  the  pores  of  the  tree,  and  vary  in  composition 
in  the  different  kinds  of  trees.  Such  substances  are 
resin,  gum,  tannin,  albumen,  etc.,  among  which  there  are 
some  in  whose  chemical  composition  there  is,  in  addition 
to  carbon,  hydrogen,  and  oxygen,  a  fourth  element,  nitro- 
gen. It  has  recently  been  affirmed  that  in  addition  to  the 
fibre  there  is  in  all  wood  a  considerable  quantity  of 
another  solid  containing  more  carbon.  But  this  substance, 
which  has  been  named  lignin,  no  one  has  as  yet  shown  to 
exist  by  itself,  and  we  may  therefore  say  that  the  compo- 
sition of  wood  is  not  yet  thoroughly  known.  [See  Appen- 
dix, Note  L]  The  inorganic  substances  which  the  asp 
contains  are  principally  lime,  potash,  soda,  magnesia, 
oxide  of  iron,  oxide  of  manganese,  silica,  chlorine,  sulphur, 
sulphuric  acid,  phosphorus  and  phosphoric  acid,  and  it  is 
these  elements,  according  to  what  has  been  stated  above, 
that  after  the  wood  is  burned,  form  the  ashes,  which  are 
chiefly  composed  of  silica,  silicate  of  lime,  carbonate  of 
lime,  carbonate  of  potash,  and  carbonate  of  soda.  It  is 
clear  that  the  last-mentioned  organic  and  inorganic  ele- 
ments, which  the  sap  transmits  to  the  wood,  must  make 
the  chemical  combination  of  the  wood  different  from  the 
combination  in  the  pure  fibre,  and  even  the  wood  in  one 
species  of  tree  different  from  the  wood  in  another ;  and 
finally,  it  is  clear  that  the  age  of  the  tree,  the  soil,  climate, 
etc.,  influence  the  chemical  proportions ;  but,  generally 
speaking,  we  may  regard  perfectly  dry  wood  as  containing 


4:  HAND-BOOK   FOE   CHARCOAL    BURNERS. 

50  parts  of  carbon,  6  of  hydrogen,  42  of  oxygen,  and  1 
part  of  nitrogen  and  1  of  inorganic  substances  producing 

wood. 

The  Moisture  of  Wood. 

In  order  that  the  wood  may  get  the  composition  men- 
tioned above,  or  in  other  words,  that  the  water  of  the  sap 
may  entirely  evaporate,  a  drying  temperature  is  required 
of  about  216°  Fahr.,  while  wood  which  is  dried  in  the  air 
by  ordinary  summer  heat,  and  under  even  quite  favorable 
circumstances,  still  retains  a  considerable  amount  of 
water.  Our  common  species  of  trees  may  be  regarded  as 
consisting  of  80  parts  of  perfectly  dry  wood  and  20  parts 
water.  If  the  drying  in  the  air  is  imperfect,  the  moist- 
ure increases  in  proportion  to  the  solidity  of  the  wood, 
and  24  or  25  per  cent,  water  is  by  no  means  unusual. 
Wood  that  has  been  cut  down  a  long  time  and  dried  in 
the  air  may  likewise,  in  damp  weather,  freshets,  etc., 
absorb  a  great  deal  of  water.  It  may  be  accepted  as  a 
rule  that  the  less  porous  the  wood  is,  the  longer  time 
it  takes  to  dry  it. 

The  moisture  of  newly-cut-down  trees  differs  very  much 
in  different  kinds  of  trees,  being  greater  in  those  that 
have  a  more  porous  wood,  and  less  in  those  in  which  the 
inter-cellular  spaces  between  the  fibres  are  smaller  and 
fewer  ;  trees  of  the  same  kind  contain,  when  cut  down,  a 
very  different  quantity  of  water,  according  to  the  quality 
of  the  soil,  the  age  of  the  tree,  the  climate,  and  especially 
the  season  of  the  year.  The  more  solid  kinds  of  wood 
may  contain  less  than  30  per  cent,  of  water,  the  more  po- 


HAND-BOOK   FOE   CHARCOAL    BURNERS.  5 

rous,  on  the  other  hand,  40  to  50  per  cent.  In  rich  and 
deep  soil,  in  a  locality  protected  from  severe  winds,  the 
tree  grows  faster,  but  then  generally  becomes  more  porous, 
and  therefore  contains  more  water ;  while  unprotected 
trees  are  more  solid,  and  have  smaller  capillaries  and  cells 
for  the  flow  of  the  sap.  The  moisture  in  brush  and  young 
trees  is  greater  than  in  mature  trees  (at  the  age  of  30  to 
40  years),  since  in  the  latter  the  capillaries  gradually  be- 
come filled  with  solid  wood.  Wood  that  has  commenced 
to  decay — for  instance,  in  trees  that  have  been  blown  down 
by  the  wind — absorbs  more  water  than  wood  that  is  mature 
and  still  sound.  Stumps,  roots,  and  limbs  are  more  solid, 
contain  more  wood  and  less  sap  than  the  stem  itself.  But 
it  is  especially  important  to  observe  the  season  of  the  year 
when  the  tree  is  cut  down.  It  has  been  mentioned  above 
that  the  sap  ascends  and  descends,  while  the  tree  is  healthy, 
in  the  capillaries,  or  vessels  situated  between  the  fibres. 
This  circulation,  is  not  the  same  during  the  different  sea- 
sons of  the  year.  It  is  most  lively  in  the  spring,  and  we 
'then  say  that  the  sap  rises.  Circulation  continues  during 
summer  and  the  beginning  of  autumn,  but  it  gradually 
decreases,  and  finally  ceases  entirely  in  the  latter  part  of 
autumn,  after  which  the  tree  remains  in  a  torpid  state  un- 
til the  following  spring,  when  the  sap  begins  to  rise  again. 
It  has  also  already  been  mentioned  that,  during  the  winter 
months,  starch  is  deposited  from  the  nourishment  which 
the  organs  of  the  tree  collected  during  the  previous  sum- 
mer. From  all  this  it  clearly  follows  that,  as  a  general 
rule,  trees  that  are  felled  late  in  the  fall  and  during  the  win- 


6  HAND-BOOK    FOR   CHARCOAL    BURNERS. 

ter  months — that  is  to  say,  from  the  month  of  November 
until  about  the  middle  of  March — contain  more  solid  wood 
and  less  sap  than  trees  felled  in  any  other  season  of  the 
year.  It  has  been  found,  by  experiment,  that  the  moisture 
in  different  kinds  of  trees  that  have  been  cut  in  the  be- 
ginning of  April  has  been  7  to  10  per  cent,  greater  than 
iu  the  same  kinds  of  trees  felled  in  the  latter  part  of  Jan- 
uary. 

Natural  Seasoning  of  Wood. 

While,  as  will  be  shown  hereafter,  only  that  wood  sea- 
soned in  the  air,  which  we  call  natural  seasoning,  should  be 
used  in  making  charcoal,  it  is  important  to  know  every- 
thing that  can  aid  us  in  producing  a  seasoning  of  this 
kind.  The  first  thing  we  have  to  call  attention  to  is  that 
the  seasoning  takes  place  sooner  when  the  brandies  are 
not  cut  off,  and  the  felled  tree  is  permitted  to  lie  on  its 
branches  as  long  as  the  pine  needles  remain ;  the  natural 
explanation  of  this  is  that  the  fresh  and  green  pine  nee- 
dles on  the  branches  evaporate  a  great  quantity  of  water, 
which  they,  even  long  after  the  tree  is  cut  down,  draw 
from  its  stem  and  branches.  We  are,  however,  certain  of 
this  fact  only  when  the  tree  is  felled  during  the  season 
when  the  sap  is  in  circulation.  Whether  pine  needles  of 
trees  cut  during  winter  absorb  water  from  the  stem  and 
other  parts  of  the  tree  to  any  considerable  extent,  has  not 
yet  been  discovered,  but  it  is  scarcely  probable.  [See 
Appendix,  Note  II.] 

In  the  next  place,  the  seasoning  of  the  wood  is  promoted 
by  splitting  lengthwise  at  least  all  the  thicker  parts  of  the 


HAND-BOOK   FOR    CHARCOAL    BURNERS.  7 

tree.  Still  this  may  seem  to  many  to  involve  too  much 
expense  and  too  much  loss  of  time ;  the  same  end  may 
possibly  be  reached,  but  in  a  longer  time,  by  hewing  off 
lengthwise  two  to  six  strips  of  bark  the  breadth  of  the 
axe.  The  bark  is  almost  entirely  impervious  to  water,  and 
as  Ions:  as  it  remains  on  the  tree  unbroken  the  tree  dries 

ZD 

but  little,  and,  we  may  say,  it  dries  only  from  the  ends. 
It  has  also  been  determined,  by  experiments,  that  of  trees 
of  unequal  length  and  thickness,  all  felled  at  the  same 
time  in  the  month  of  June  and  brought  under  cover,  a 
part  being  entirely  stripped  of  their  bark,  and  a  part  re- 
taining the  bark  whole,  the  former  had  already,  in  July, 
lost  34.53  per  cent,  and  in  November  39.62,  while  the  lat- 
ter had  lost,  in  the  same  time,  0.41  to  0.98  per  cent.  In 
this  experiment,  the  longer  trees  dried  almost  as  fast  as 
the  shorter  ones;  hence,  merely  for  drying  purposes,  it  is 
of  no  great  importance  to  cut  the  trees  into  short 
pieces. 

It  is  evident  that  the  wood  will  season  more  rapidly  the 
more  it  is  exposed  to  the  sun  and  air.  Trees  should  also 
be  felled  towards  the  north,  in  order  that  the  butt  ends, 
which,  on  account  of  their  greater  thickness,  have  a  nat- 
ural tendency  to  season  more  slowly  than  the  tops,  may 
turn  to  the  south.  Then  the  limbs  cut  off  should  be  raised 
with  the  butt-ends  upon  stumps,  stones,  etc. ;  and,  finally, 
the  so-called  waste  wood,  branches,  etc.,  should  be  piled  up 
in  small  heaps,  so  as  to  allow  free  circulation  of  air 
through  them. 


8  HAND-BOOK   FOR   CHARCOAL    BURNERS. 

The  Shrinkage  of  Wood. 

A  quality  of  the  wood  which  must  be  taken  into  con- 
sideration is  its  shrinkage  in  drying.  The  extent  of  this 
change  varies  in  different  kinds  of  trees,  and  even  wood  of 
the  same  kind  of  tree  does  not  shrink  alike,  the  shrinking 
being  greater  in  the  wood  of  trees  that  have  been  shel- 
tered than  of  those  that  have  been  less  protected — in  wood 
of  mature  trees  than  in  brushwood,  etc.  Hence  it  is  very 
difficult  to  express  in  figures  the  approximate  amount  of 
shrinkage,  which,  by  the  way,  is  much  less  lengthwise  the 
wood  than  crosswise.  In  the  latter  manner  the  shrinkage 
in  the  open  air  amounts  to  several  per  cent,,  as  we  may 
observe  in  floors  that  have  been  made  of  green  planks.  It 
is  this  shrinking  of  the  wood  that  in  change  of  weather 
warps  doors  and  windows  and  cracks  wooden  vessels. 

Wood  Heated  in  a  Covered   Vessel. 

If  a  piece  of  green  wood  containing  about  60  per  cent 
solid  wood  and  40  per  cent,  water  is  heated  gradually  in 
a  covered  vessel,  as  in  an  iron  retort,  which  is  furnished 
with  a  small  vent  for  the  escape  of  steam,  etc.,  but  with- 
out permitting  the  outside  air  to  come  into  any  considera- 
ble contact  with  the  interior  of  the  vessel,  then  it  follows 
from  what  has  been  stated  that  a  part  of  the  water  evap- 
orates quite  easily,  until  the  wood  assumes  the  condition 
of  wood  that  has  been  subject  to  natural  seasoning,  that  is 
to  say,  80  per  cent,  solid  wood  and  20  per  cent,  water,  and 
that  when  the  heat  is  afterwards  increased  to  216°  Fahr. 


HAND-BOOK    FOR    CHARCOAL    BURNERS.  9 

the  water  contained  in  the  sap  escapes,  leaving  50  per 
cent,  carbon  and  50  per  cent,  of  hydrogen  and  oxygen. 

Of  course  the  piece  of  wood  gradually  loses  in  weight 
just  as  much  as  the  weight  of  water  that  escapes,  so  that, 
when  at  last  only  the  solid  wood  remains,  the  piece  of 
wood  containing  the  above-mentioned  proportions  will 
have  only  60  per  cent,  of  its  original  weight.  If  we  now 
increase  the  heat  of  the  retort  which  contains  the  piece  of 
wood  that  has  been  thus  dried,  then  its  volatile  substances, 
the  oxygen,  hydrogen,  nitrogen,  strive  with  increased 
power  to  reassume  the  form  of  gas.  This  is  true  of  all  or- 
ganic substances  without  exception,  although  some  may 
require  more  heat  than  others.  Knowing  now,  as  we  do, 
that  the  solid  wood  contains  oxygen  and  hydrogen  in 
about  the  same  proportions  of  weight  to  form  water  or 
steam,  and  from  chemistry  that  both  these  elements  have  a 
great  tendency  to  unite  and  form  water,  also  that  if  we 
mix  hydrogen  and  oxygen  in  about  the  same  proportions 
in  which  they  are  found  in  wood  this  mixture  is  very 
easily  ignited,  producing  a  terrible  explosion  with  a  high 
degree  of  heat,  it  would  be  natural  to  conclude  that  in  the 
case  before  us,  the  trifling  amount  of  nitrogen  in  the  wood 
not  being  considered,  the  oxygen  and  hydrogen  could  be 
made  to  unite  almost  without  taking  away  any  of  the  car- 
bon in  the  wood.  In  other  words,  we  would  naturally 
conclude  that  but  little  of  the  carbon  would  need  to  be 
lost  by  this  heating  of  the  wood.  Such  is,  however,  not  the 
case.  Together  with  the  steam  escape  in  the  gaseous  form 
all  other  kinds  of  chemical  elements  containing  a  consid- 


10  HAND-BOOK    FOR   CHARCOAL    BURNERS. 

erable  amount  of  carbon.  That  the  steam,  which  escapes 
from  the  wood  after  the  heat  has  been  increased  to  more 
than  216°  Fahr.,  is  in  its  composition  something  else  than 
pure  water,  may  be  easily  discovered  from  the  fact  that 
it  changes  color,  becomes  dark  and  dirty,  and  emits  an  of- 
fensive smell,  and  when  this  steam  is  properly  cooled  and 
condensed  we  find  that  it  contains  carbonic  acid,  carbonic 
oxide,  carbnretted  hydrogen,  partly  watery  liquid  sub- 
stances, such  as  water  and  pyroligneous  acid,  partly  oily 
liquid  and  offensive  smelling  substances  in  a  mixed  state 
known  by  the  name  of  tar  and  pitch.  When  at  last  all 
oxygen,  hydrogen  and  nitrogen  have  escaped,  for  which  a 
red  glowing  heat  is  required,  then  there  remains,  in  addi- 
tion to  the  trifling  amount  of  inorganic  substances,  only 
that  part  of  the  original  quantity  of  carbon  which  has  not 
been  carried  away  by  the  oxygen  and  hydrogen.  It  is 
true,  a  little  hydrogen  remains,  and  this  can  scarcely  be 
taken  out  by  a  white  heat,  but  the  quantity  is  so  trifling 
that,  from  a  technical  point  of  view,  it  needs  no  consider- 
ation. The  gaseous  mixture  is  not  combustible  so  long  as 
it  contains  any  considerable  amount  of  water,  but  after- 
wards it  is  easily  ignited  and  continues  to  burn. 

Although  quite  an  amount  of  carbon  is  lost  in  this 
manner,  still  it  has  been  found  that  the  extent  of  the  loss 
may  vary  widely.  It  is  therefore  of  the  greatest  import- 
ance to  find  out  the  cause  of  the  comparatively  greater  or' 
less  loss  of  carbon. 

By   exact   experiments  it   has  been   found  that  wood, 
which  has  been  well  dried  in  the  air,  and  which  may  be 


HAND-BOOK   FOR   CHARCOAL   BURNERS.  11 

regarded  as  consisting  of  80  per  cent,  solid  wood  (40  per 
cent,  carbon  and  40  per  cent,  hydrogen  and  oxygen)  and 
20  per  cent,  water,  if  it  is  slowly  heated  up  to  270°  Fahr. 
in  a  retort  loses  about  57  per  cent,  of  its  weight ;  that  the 
remaining  43  per  cent,  consists  of  a  brownish  substance, 
which  still  contains  the  greater  portion  of  the  carbon,  also 
a  considerable  amount  of  hydrogen  and  oxygen ;  that  this 
brownish  substance  must  needs  be  heated  to  a  red  heat  in 
order  to  set  free  the  last  two-named  elements  ;  that  in  this 
last  heating  process  comparatively  more  carbon  is  lost ; 
and  that  the  black  charcoal  thus  produced  contains  in 
weight  at  least  not  more  than  25  per  cent,  of  the  weight 
of  the  wood  seasoned  in  the  air.  Moreover,  it  has  been 
found  that  the  sooner  the  heating  is  brought  to  a  red  heat, 
that  is  to  say,  the  higher  the  average  temperature  of  the 
heat  used  in  changing  wood  to  charcoal  is,  the  less  will  be 
the  amount  of  charcoal  left,  which,  when  the  heating  pro- 
cess is  made  as  rapid  as  possible,  may  even  be  reduced  to 
12  or  13  per  cent,  of  the  weight  of  the  wood.  The  reason 
for  this  great  difference  in  the  results  is,  that  the  higher 
the  temperature  is  in  which  an  organic  substance  is  car- 
bonized, the  greater  becomes  also  the  tendency  of  the  car- 
bon to  unite  and  escape  with  the  oxygen  and  hydrogen ; 
carbon  is  then  found  in  the  greater  proportion  in  the  first 
steam  and  gas  escaping  from  the  organic  substance. 
Hence  as  much  as  70  per  cent,  of  the  carbon  in  the  dry 
wood  can  be  wasted,  and  even  under  the  most  favorable 
circumstances  40  per  cent,  is  lost.  In  other  words,  from 
100  parts  green  wood  we  never  get  more  than  about  20 


12  HAtfD-BOOK   FOR  CHARCOAL   BURNERS. 

per  cent,  charcoal,  and  if  the  coaling  is  hastened  as  much 
as  possible  with  a  high  temperature  from  the  beginning 
we  get  only  9  or  10  per  cent. 

Combustion  of  Wood  in  the  Open  Air. 

Above,  the  combustion  was  supposed  to  take  place  in  a 
covered  vessel.  Now  we  have  to  consider  what  takes 
place,  if  the  piece  of  wood  is  heated  in  the  open  air — for 
instance,  over  a  hot  oven.  Even  now  it  is  only  watery 
steam  that  escapes  in  the  beginning,  while  a  part  of  this  is 
usually  condensed  on  colder  parts  of  the  unevenly  heated 
wrood,  which  parts  consequently  get  a  moist  appearance, 
and  we  then  say  that  the  wood  sweats.  In  the  same  de- 
gree as  the  heat  is  increased,  the  water  evaporates,  the 
drying  piece  of  wood  everywhere  reassumes  a  dry  appear- 
ance, and  when  the  heat  has  reached  216°  Fahr.  all  the 
water  in  the  sap  is  driven  out.  If  a  burning  chip  or  a  red 
hot  coal  is  put  into  the  steam  issuing  forth  from  all  the 
pores  of  the  wood,  then  the  fire  in  the  chip  or  coal  sur- 
rounded by  this  steamy  atmosphere  will  be  extinguished. 
If  the  piece  of  wood  is  heated  still  more,  the  solid  wood 
begins  to  break ;  first  the  exterior  and  then  the  interior 
parts  assume  a  brown  and  finally  a  perfectly  black  color, 
and  here  we  also  apply  the  general  rule,  that  the  sooner 
the  heat  is  brought  to  a  red  glow,  the  more  carbon  will  be 
contained  in  the  steam  and  gases  that  escape,  and  the  less 
charcoal  will  be  left.  If  we  could  check  the  draft  some- 
what we  would  find  that  the  atmospheric  substances  form 
a  more  or  less  complete  covering.  If  it  were  now  possi- 


HAND-BOOK   FOR   CHAKCOAL    BURNERS.  13 

ble  to  keep  the  piece  of  wood  perfectly  surrounded  by 
this  gaseous  -covering,  then  this  would  clearly  serve  the 
same  purpose  as  the  walls  of  the  retort  in  the  previous  il- 
lustration, but  this  can  never  be  done,  for  it  always  hap- 
pens, when  the  charcoal  by  means  of  the  higher  tempera- 
ture begins  to  get  red,  that  the  combustible  vapors  and 
gases,  which,  according  to  the  above  explanation,  are 
always  found  in  greater  or  less  quantities  in  this  covering, 
ignite  immediately  by  coming  in  contact  with  the  outside 
air  and  the  glowing  charcoal.  The  same  takes  place,  also, 
if  we,  before  the  charcoal  begins  to  glow,  bring  from  the 
outside  any  burning  substance  into  immediate  contact 
with  the  combustible  gas  and  vapor.  We  commonly  say 
that  the  wood  burns,  but  this  is  not  the  case.  It  is  only 
the  erases,  etc.,  formed  in  the  wood  by  heating  and  issuing 

O  v  c}  O 

forth  from  it  that  burn  ;  and  a  similar  flame  is  produced 
in  the  operation  of  which  we  are  here  speaking,  if  during 
the  heating  process  in  the  covered  retort  the  atmospheric 
substances  coming  through  the  vent  are  ignited.  Common 
gaslight  is  something  of  this  kind.  When  the  gases  from 
the  wood  have  thus  been  ignited,  it  continues  to  be  more 

O 

or  less  completely  surrounded  by  the  flames  so  long  as  the 
latter  are  fed  by  new  combustible  atmospheric  substances, 
which  constantly  come  out  of  the  wood ;  but  when  finally 
all  the  volatile  substances  have  been  driven  out,  the  flame 
is  extinguished.  The  charcoal  remaining,  if  the  high 
temperature  is  kept  up,  continues  to  glow,  and  sends  out 
hero  and  there  small  bluish  transparent  flames,  of  an  en- 
tirely different  appearance  and  quality  than  those  men- 


1-i  HAND-BOOK   FOB   CHARCOAL    BURNERS. 

tioned  above,  which  usually  are  highly  colored  and  not 
transparent.  Now  we  can  say  in  a  true  sense  that  the 
charcoal  itself  burns,  whereby  are  formed  the  gaseous 
combinations  of  carbon  and  oxygen,  which  are  known  by 
the  names  of  carbonic  oxide  and  carbonic  acid.  If  this 
burning  continues  long  enough,  there  will  at  last  remain 
only  the  inorganic  elements  in  the  form  of  light  gray 
ashes.  The  carbonic  oxide  contains  far  less  oxygen  than 
the  carbonic  acid,  and  it  is  the  burning  of  the  carbonic 
oxide  gas  to  carbonic  acid  gas  that  produces  the  bluish 
flames.  When  the  development  of  gas  ceases,  that  is  to 
say,  as  soon  as  the  flame  dies  out  for  want  of  nourishment, 
if  then  the  glowing  charcoal  that  remains  is  shut  out  from 
contact  with  the  air  and  is  cooled  off,  we  will  find  that 
what  remains  is  precisely  of  the  same  quality  as  the  char- 
coal substance  obtained  after  heating  wood  to  a  red  heat 
in  a  covered  retort.  In  the  one  as  in  the  other  the  re- 
maining portion  will  be  greater  or  less  in  proportion  as 
the  heating  process  has  been  slow  or  rapid.  In  both 
cases,  supposing  the  heating  process  to  be  stopped  at  a 
lower  temperature,  we  get  perfectly  similar  substances, 
forming  the  transition  between  wood  and  charcoal,  and  of 
which  more  below.  In  order  to  understand  more  easily 
how  combustion  in  the  open  air,  when  it  is  not  carried  too 
far,  may  leave  almost  the  same  result  as  is  produced  when 
the  combustion  takes  place  in  a  covered  retort,  we  must 
bear  in  mind  the  following  facts: — In  the  first  place,  that 
when  wood  is  burned  in  the  open  air,  it  is  surrounded  by 
a  gaseous  covering  which  more  or  less  perfectly  protects 


HAND-BOOK    FOE   CHARCOAL    BURNERS.  15 

it  from  the  immediate  action  of  the  atmosphere ;  in  the 
next  place,  that  although  by  the  waving  to  and  fro  of  the 
flames  the  atmosphere  comes  for  a  moment  in  contact 
with  the  charcoal  substance,  this  contact  is  only  with  the 
surface ;  as  long  as  the  development  of  gas  goes  on  lively 
the  inside  of  the  charcoal  is  almost  as  well  protected  from 
the  oxygen  of  the  air  as  if  the  process  took  place  in  a 
covered  retort. 

If  we  now  apply  this  experiment  to  several  pieces  of 
\vood  piled  into  a  heap,  to  be  gradually  heated  to  a  red 
heat,  we  get  of  course  a  more  complicated  result,  espe- 
cially as  the  combustion  will  vary  in  rapidity  in  different 
parts  of  the  heap,  and  as  this  is  more  exposed  to  the  air 
in  some  parts  than  in  others,  but  the  results  will  be  the 
same  in  character  as  those  obtained  when  only  one  piece 
of  wood  was  coaled.  To  be  convinced  of  this  we  only 
need  to  observe  the  process  going  on  in  the  fireplace  of 
every  cooking  stove.  When  the  fire  is  kindled  in  the 
stove,  the  carbonic  gases  of  the  wood  burn  with,  a  flame, 
which  covers  at  least  the  upper  part  of  the  fire  and 
develops  a  heat  which  is  sufficient  to  coal  even  large 
blocks,  if  these  are  dry  when  they  are  put  into  the  fire. 
On  account  of  this  continued  process  of  making  charcoal, 
new  combustible  gases  are  constantly  being  developed 
which  feed  the  flame,  and  also  prevent  to  a  considerable 
extent  the  consumption  of  the  charcoal.  But  below, 
where  the  air  has  the  most  easy  access  to  the  charred  wood, 
the  charcoal  is  consumed,  the  fire  falls  down,  so  that  at 
last  hardly  anything  but  ashes  remain. 


16  HAND-BOOK   FOR   CHARCOAL   BURNERS. 

Combustion  of  Wood  with  a  limited  Amount  of  Air. 

Now  we  have  to  show  what  effect  it  lias  when  the  air 
strikes  the  heated  wood  in  only  one  direction,  on  the  sup- 
position also  that  the  admittance  of  the  air  or  draught  can 
be  regulated  at  pleasure.  Suppose  several  long  pieces  of 
wood,  thoroughly  seasoned  in  the  air,  be  put  into  an  iron 
pipe  open  at  both  ends,  and  that  the  air  is  drawn  in 
through  one  of  the  openings  which  we  will  call  A,  and 
passes  out  through  the  other  opening,  B.  If  we  set  fire  to 
the  pieces  at  A,  the  flames  will  pass  along  close  to  the  sides 
of  the  pipe  and  have  a  drying  effect  upon  the  wood, 
along  the  whole  length  of  the  pipe,  but  the  effect  is 
greatest  near  the  place  of  kindling  the  fire  at  A.  where 
the  drying  process  in  a  short  time  will  produce  charcoal. 
The  greater  or  less  rapidity  with  which  this  is  done  de- 
pends upon  the  strength  of  the  draught,  and  upon  this  also 
depends  how  far  into  the  pipe  the  burning  of  the  gas 
extends.  Without  further  explanation,  it  will  be  easily 
observed  that  it  cannot  be  long  before  -at  the  opening  A, 
where  there  is  a  constant  supply  of  fresh  air,  the  charcoal 
produced  will  be  gradually  consumed,  so  that  only  ashes 
remain.  This  may  have  taken  place  at  this  end  before 
the  pieces  at  the  end  B  have  become  perfectly  dry.  If 
the  burning  continues  until  the  wood  of  half  the  length 
of  the  pipe  is  charred  we  will  find  that,  at  the  end  A,  a 
large  portion  has  already  been  consumed,  leaving  nothing 
but  ashes ;  that,  nearest  the  end  A,  a  part  of  the  charcoal 
has  not  yet  been  consumed,  but  that  the  remaining  portion 


HAND-BOOK   FOE   CHARCOAL    BURNERS.  17 

is  very  porous  and  spongy ;  and  finally  we  will  find  that, 
farther  into  the  pipe,  the  charcoal  gradually  changes  from 
this  porous  and  almost  feather-light  quality  to  solid  char- 
coal, which  is  formed  in  the  centre  of  the  pipe's  length. 
If  we  now  investigate  farther  what  the  other  half  of  the 
pipe  contains  we  will  there  find  a  gradual  transition  from 
perfect  charcoal  in  the  middle  of  the  pipe  to  a  less  com- 
pletely coaled  product,  in  which  the  charring  gradually 
affects  more  and  more  the  exterior  parts  of  the  wood,  un- 
til we  finally  reach  a  point,  where  not  only  the  inside 
parts  of  the  wood,  but  also  the  exterior  parts,  have  merely 
become  thoroughly  dried.  If  this  charring  is  continued 
still  farther,  it  advances  gradually  from  A  to  B,  and  finally 
the  complete  charring  reaches  the  latter  point.  The  pipe 
now  contains  no  more  wood,  but  only  a  part,  charcoal, 
which  is  of  the  more  porous  quality  the  farther  it  lies  from 
B,  and  a  far  greater  part  ashes.  Such  an  arrangement  as 
the  one  here  described,  in  which  the  principal  point  is 
that  the  draught  is  in  the  same  direction  as  that  in  which 
the  burning  progresses,  must  be  very  desirable,  where  wre 
want  the  ignited  material  to  turn  to  ashes  as  rapidly  and 
completely  as  possible,  and  is  worth  paying  attention  to 
in  the  construction  of  fireplaces,  in  furnaces  and  the  like, 
and  even  in  the  construction  of  common  cooking  stoves 
we  will  discover  a  more  or  less  faithful  observance  of  this 
general  rule,  which  may  be  stated  in  the  following  man- 
ner:— The  draft  should  be  conducted  from  the  point 
where  the  fire  is  kindled  along  or  through  the  fuel 
which  is  inside  and  has  not  become  ignited.  The  result 


18  HAND-BOOK   FOR    CHARCOAL    BURNERS. 

will  be  quite  different  if  the  fire  is  kindled  at  B.  Even 
now  the  drying  of  the  wood,  the  driving  out  and 
burning  of  the  gases  formed  in  the  wood,  and  the  com- 
plete charring  of  the  wood  from  one  end  of  the  pipe  to  the 
other,  progresses,  but  the  progress  is  made  in  the  direction 
from  B  to  A,  which  is  opposite  the  direction  from  A  to  B, 
in  which  the  current  of  air  moves.  The  progress  is  there- 
fore more  slow,  the  general  temperature  is  lower,  which, 
according  to  what  has  already  been  stated,  of  itself  mate- 
rially aids  the  production  of  good  charcoal.  But  from  the 
fact,  which  is  of  more  importance,  that  the  parts  of  the 
wood  that  have  become  charred  come  in  contact  only 
with  the  gases  which  constantly  are  formed  near  A,  and 
which,  the  draft  being  well  regulated,  do  not  contain 
any  free  oxygen,  and  are  protected,  as  will  be  shown  below, 
from  consumption,  of  course  not  perfectly,  but  still 
incomparably  better  than  when  the  wood  was  kindled  at 
A.  We  may  therefore  conclude  that,  if  the  experiment 
is  made  with  care,  when  the  charring  process  reaches  A, 
there  will  take  place  no  burning  to  ashes  near  B,  but  the 
charcoal  near  B  will  be  less  solid  and  heavy  than  charcoal 
near  A.  To  get  good  charcoal,  then,  in  the  greatest  pos- 
sible quantity,  it  is  a  principal  rule  that  the  draught  should 
be  conducted  in  the  opposite  direction  to  that  in  which 
the  charring  progresses.  It  must  be  observed  that  even  in 
this  manner  we  may  get  a  trifling  amount  of  charcoal,  and 
that  it  may  be  of  a  poor  quality.  This  happens  either  if 
the  draught  is  too  strong,  so  that  the  air,  after  it  has  passed 
the  point  where  the  charring  takes  place  still,  contains  free 


HAND-BOOK   FOR   CHARCOAL    BURNERS.  19 

oxygen,  which  consumes  the  charcoal  already  formed,  or 
if,  to  return  to  the  illustration  given,  the  process  is  con- 
tinued after  the  charring  has  reached  A.  The  charcoal 
at  A,  which  was  formed  last,  will  now  first  turn  to  ashes, 
and  it  will  take  a  long  time  before  the  whole  of  the  char- 
coal from  A  to  B  is  consumed.  What  has  now  been  said 
about  the  combustion  of  the  wood,  the  air  being  limited, 
may  be  considered  the  general  rule,  but  we  also  know 
that  even  the  gaseous  combustible  substances,  watery 
steam  and  carbonic  acid,  when  they  pass  through  a  glow- 
ing mass  of  charcoal,  gradually,  yet  far  more  slowly  than 
the  atmosphere,  consume  the  charcoal,  forming  especially 
carbonic  oxide  and  hydrogen.  This  experience,  which 
corresponds  faithfully  with  what  has  been  said  about  the 
unlike  results,  when  the  process  of  making  charcoal  takes 
place  rapidly  or  slowly,  with  a  high  or  low  temperature, 
it  is  important  to  apply  when  making  charcoal  on  a  large 
scale,  as  will  be  shown  further  on. 


20  HAND-BOOK   FOE   CHARCOAL   BURNERS. 


CHAPTER  II. 

CHARCOAL. 

Its  General  Qualities. 

THE  products  produced  in  charring  wood  are,  as  has 
been  shown,  of  many  kinds — solid,  liquid,  and  gaseous ; 
but  among  these  there  is  only  one,  charcoal,  which  requires 
a  more  detailed  treatment  here.  Charcoal,  made  with 
proper  care  from  good  material,  retains  distinctly  the  tex- 
ture of  the  wood  ;  its  color  is  black,  fracture  glossy,  and 
when  it  falls  upon  any  hard  object  it  produces  a  ringing 
sound.  It  sustains  a  heavy  weight,  if  gently  laid  upon  it, 
but  breaks  easily  by  a  light,  quick  blow.  When  newly 
broken,  it  freely  soils  the  fingers.  It  floats  upon  water, 
the  latter  being  much  heavier.  If  such  a  piece  of  char- 
coal is  burned  in  the  open  air,  it  will  be  consumed  with- 
out flame  or  smoke.  But  it  is  not  usual  that  a  heap  of 
charcoal  consists  exclusively,  or  even  mainly,  of  charcoal 
of  this  quality.  We  everywhere  find  mixed  with  it  char- 
coal of  a  color  verging  on  brown,  which  is  more  ponder- 
ous, and  is  particularly  distinguished  by  the  fact  that  in 
combustion  it  sends  forth  smoke  and  burns  with  a  flame. 
These  qualities  distinctly  show  that  the  charring  has  not 
been  complete — in  other  words,  that  the  organic  composi- 


HAND-BOOK   FOR   CHAECOAL   BURNERS.  21 

tion  of  the  wood  has  not  been  completely  destroyed,  but 
that  the  charcoal  still  contains  a  considerable  portion  of 
hydrogen  and  oxygen.  Still  more  frequently  is  found 
charcoal,  the  color  of  which  is  indeed  black,  but  which 
has  lost  more  or  less  of  the  original  wood  texture,  and  has 
a  dull,  lustreless  appearance ;  it  is  also  very  light  and  po- 
rous, crumbles  to  pieces  by  a  very  light  pressure,  and 
freely  soils  the  lingers.  Such  charcoal  is  generally  pro- 
duced, either  if  in  charring  the  temperature  has  been, 
high,  or  if  the  already  formed  and  yet  glowing  charcoal, 
by  means  of  improper  draught,  has  been  allowed  to  re- 
main in  contact  with  the  atmospheric  air  or  with  the  gase- 
ous substances  produced  by  charring.  But  even  by  proper 
and  careful  work  such  charcoal  is  produced  from  sour 
wood  and  from  wood  that  has  commenced  to  decay.  [See 
Appendix,  Note  III.]  Charcoal  which,  from  improper 
care,  contains  much  water  or  ico,  is  heavier,  sometimes  so 
heavy  that  it  sinks  in  water.  It  is  also  without  ring  or 
lustre,  burns  with  difficulty,  and  develops  much  watery 
steam  in  combustion. 

The  Chemical  Composition  and  Moisture  of  Charcoal. 

It  has  already  been  stated  that  perfectly  dry  wood  may 
be  regarded  as  consisting  of  about  50  parts  carbon,  6  parts 
hydrogen,  42  parts  oxygen,  1  part  nitrogen,  and  1  part 
substances  forming  ash ;  and,  under  the  most  favorable 
circumstances,  at  least  40  per  cent,  of  the  carbon  is  lost 
in  charring.  With  these  figures  as  a  basis,  100  parts  per- 
fectly dry  wood  ought  to  produce  30  parts  chemically  pure 


22  HAND-BOOK   FOR   CHAECOAL    BURNERS. 

carbon  and  1  part  ash,  to  which  must  be  added  a  little 
hydrogen,  since,  as'we  have  explained,  the  last  portion  of 
hydrogen  requires  a  very  high  and  persistent  combustion 
to  be  driven  out.  We  may  conclude,  therefore,  that  the 
charcoal  product,  under  favorable  circumstances,  contains 
96  parts  chemically  pure  carbon,  1  part  hydrogen,  and  3 
parts  ash.  It  is  also  clear  that  the  more  porous  the  char- 
coal is,  the  greater  is  the  amount  of  ash  in  proportion 
to  the  amount  of  pure  charcoal ;  on  the  other  hand,  the 
more  imperfect  the  charring  process  has  been,  the  greater 
will  be  the  amount  of  ash  in  proportion  to  the  amount 
of  pure  charcoal.  But  the  charcoal  not  being  a  solid  sub- 
stance, but  always  somewhat  porous  and  sometimes  very 
much  so,  it  contains,  in  addition  to  carbon  and  ash,  air 
and  water,  generally  both.  The  air  we  need  not  consider, 
but  the  amount  of  water  which  the  charcoal  contains  has 
a  far  greater  influence  upon  its  quality,  and  must  not  be 
overlooked.  Fresh  charcoal,  as  also  reheated  charcoal,  con- 
tains scarcely  any  water,  but  when  cooled  it  absorbs  it  very 
rapidly,  so  that,  after  24  hours,  it  may  contain  4  to  8  per 
cent,  water.  After  that  time  the  absorption  of  water  pro- 
ceeds more  slowly,  but  of  course  the  dampness  of  the  air, 
the  species  of  wood,  the  greater  or  less  porousness  of  the 
charcoal,  the  kind  of  protection,  etc.,  have  an  influence  to 
hasten  or  delay  the  absorption  of  water.  After  the  lapse 
of  a  few  weeks  the  moisture  of  the  charcoal  may  not  in- 
crease perceptibly,  and  may  be  estimated  at  10  to  15  per 
cent.,  or  an  average  of  12  per  cent.  A  thoroughly  charred 
and  dry  piece  of  charcoal  ought,  then,  to  contain  about 


HAND-BOOK   FOR   CHARCOAL    BURNERS.  23 

84  parts  carbon,  1^  parts  water,  3  parts  ashes,  and  1  part 
hydrogen.  That  charcoal  made  from  more  solid  kinds  of 
wood  absorbs  less  water,  while  porous,  partially  dried  char- 
coal absorbs  more,  needs  no  explanation.  When  the  char- 
coal contains  much  water,  not  only  does  the  water  espe- 
cially reduce  its  value  as  a  fuel,  but  it  also  injures  it  in 
another  way.  If  the  water  in  a  piece  of  porous  charcoal 
freezes  to  ice,  the  ice  breaks  the  charcoal  into  piec.es,  and 
it  is  thus  partially  reduced  to  charcoal  dust. 

How  Charcoal  varies  in  Weight  and  Quality. 

The  weight  of  the  charcoal  depends  much  upon  the 
greater  or  less  quantity  of  water  it  contains,  and  it  has 
already  been  shown  that  light  and  porous  charcoal,  after 
absorbing  as  much  water  as  possible,  may  even  become 
heavier  than  water. 

By  boiling  ordinary  good  charcoal  in  water,  we  may  in- 
crease its  moisture  to  a  very  considerable  extent.  Hence 
we  would  make  a  great  mistake,  if  we  only  from  the 
greater  or  less  weight  of  the  charcoal  were  to  decide  in 
regard  to  its  quality :  and,  from  another  point  of  view, 
the  same  is  true  even  of  newly-made  charcoal.  Black, 
solid,  and  perfectly  good  charcoal  is  indeed  heavier 
than  that  which  is  loose  and  porous,  but,  on  the  other  hand, 
it  is  lighter  than  that  which  has  not  been  thoroughly 
charred.  Regardless  of  the  moisture  and  the  mariner  of 
charring,  the  charcoal  of  some  kinds  of  wood  is,  of  itself, 
considerably  heavier  than  that  made  of  other  kinds  ;  char- 
coal made  from  foliferons  trees  is  usually  heavier  and  more 


24:  HAND-BOOK   FOB   CHARCOAL   BURNERS. 

solid  than  that  made  from  coniferous  trees.  Young  trees 
produce  lighter  charcoal  than  older  ones;  trees  felled  in 
winter  produce  a  stronger  charcoal  than  those  felled  in 
summer.  Well-seasoned  wood  produces  better  charcoal 
than  green  wood.  In  determining  the  quality  of  charcoal, 
then,  it  is  necessary  both  to  see  and  weigh  it.  From  all 
this,  it  is  perfectly  natural  that  the  figures  given  to  rep- 
resent the  weight  of  charcoal  differ  very  much.  As  a  gen- 
eral rule,  we  may  assume  that  a  cubic  foot  of  charcoal 
carefully  made  from  well-seasoned  pine  weighs  about  9 
pounds,  and  a  cubic  foot  made  from  spruce  8  pounds. 

The  Shrinking  of  Wood  in  Charring. 

"We  already  know  that  wood  shrinks  in  drying.  Although 
this  shrinkage  is  not  insignificant,  it  is  far  less  than  that 
which  takes  place  in  charring.  To  determine  the  extent 
of  this  decrease  in  volume  is  quite  difficult,  since  the  char- 
coal always  contains  larger  or  smaller  cracks  or  open  spaces, 
in  consequence  of  which  the  shrinkage  seems  less  than  it 
really  is.  But  the  experiments,  which  were  made  very 
carefully  by  Uhr,  have  shown  that  pine  wood  2J  years  old, 
that  had  lain  during  all  4iis  time  under  cover,  produced 
in  volume  46.5  per  cent,  charcoal,  and  spruce  produced, 
under  like  circumstances,  52  per  cent.,  in  which  experi- 
ments Uhr  regards  the  greater  per  cent,  of  volume  pro- 
duced by  spruce  wood  as  depending  upon  the  very  fact 
that  the  spruce  cracks  more  in  charring  than  the  pine. 
The  experiments  also  showed  that  the  shrinkage  is  far 
greater  crosswise  than  lengthwise  of  the  wood.  Mean- 


HAND-BOOK   FOR   CHARCOAL    BURNERS.  25 

while,  we  must  bear  in  mind  that  in  charring  large  quan- 
tities it  cannot  be  avoided  that  the  charcoal  cracks  far 
more  to  pieces,  thus  becoming  more  voluminous  than  that 
which  Uhr  obtained  by  his  experiments.  And  the  best 
proof  of  this  is  that  Uhr  himself,  by  other  experiments, 
in  which  he  could  not  so  carefully  consider  everything  that 
serves  to  diminish  the  tendency  of  the  charred  material  to 
crack  to  pieces,  obtained  from  100  parts,  volume,  of  pine, 
56  to  75  parts,  volume,  charcoal;  and  from  100  parts, 
volume,  of  spruce,  S2  to  90  parts,  volume,  of  charcoal. 
The  drier  the  wood  is  which  we  use  in  these  experiments, 
the  greater  is  the  general  result,  both  in  respect  to  volume 
and  weight  of  charcoal.  So-called  brands — wood  that  has 
been  slightly  charred  on  the  outside — produced  in  volume : 
pine,  75.63  per  cent.,  spruce,  92.98  per  cent.,  and  birch 
67.11  per  cent.,,  charcoal.  To  calculate  as  has  been  done 
in  these  experiments,  and  compare  the  cubic  measure  of 
the  really  solid  wood  and  the  actual  cubic  measurement  of 
the  charcoal  (even  without  making  allowances  for  the 
cracks)  is,  however,  not  practicable.  The  usual  method  is 
to  estimate,  from  the  outside,  the  cubic  measure  of  the 
heap,  before  charring,  and  make  allowance  for  the  space 
between  the  logs,  and  then  to  compare  with  this  measure- 
ment the  charcoal  obtained ;  the  cubic  measure  taken 
either  in  a  wagon  box,  or  otherwise,  without  deducting  any- 
thing for  the  vacant  space  between  the  pieces  of  charcoal. 
Efforts  to  make  such  comparisons  and  to  show  the  various 
results  obtained  will  be  made  in  the  proper  place. 
2 


HAND-BOOK    FOR    CHARCOAL    BURNERS. 


CHAPTEK  III. 

THE   PROCESS    OF   MAKING    CHARCOAL. 

Various  Methods  of  Making  Charcoal. 

WE  have  to  distinguish  between  two  materially  different 
methods  of  making  charcoal  :  charring  in  metiers  or 
heaps,  and  charring  in  ovens.  The  latter  method  is  in  its 
process  nothing  but  the  carrying  out  on  a  larger  scale  the 
operation  already  described,  and  consisting  in  the  combus- 
tion of  wood  in  a  covered  retort.  The  main  feature  of 
.this  method  is,  that  the  atmospheric  air  does  not  come  into 
immediate  contact  with  the  wood  to  be  charred  and  the 
charcoal  product,  and  also  that  the  heat  needed  is  produced 
outside  by  burning  separate  fuel.  [See  Appendix,  Note  II.] 
In  the  charcoal  metier,  on  the  other  hand,  the  high  charring 
temperature  is  produced  and  kept  up  by  the  combustion 
of  a  part  of  the  wood  forming  the  metier  itself,  and  even 
of  the  charcoal  produced ;  this  combustion  is  produced  by 
the  atmospheric  air  being  in  a  limited  degree  strained  as 
it  were  through  the  interior  of  the  metier.  Charring  in  an 
oven  requires  far  less  care  than  charring  in  a  metier  ;  the 
latter  method  requires  much  preparation,  skill,  and  care 
to  obtain  good  results.  Still  charring  in  metiers  is  the 
method  almost  exclusively  used  in  Sweden  and  generally 


HAND-BOOK  FOR  CHARCOAL  BURNERS.          27 

used  in  other  countries  ;  hence  the  description  of  this 
method  of  charring  forms  the  subject  of  this  handbook. 
But  of  charring  in  metiers  there  are  two  methods,  namely, 
charring  in  heaps  containing  the  wood  in  horizontal  layers, 
(lying  metiers)  and  charring  in  heaps  in  which  the  wood  is 
placed  in  nearly  vertical  layers  (standing  metiers). 

The  Usual  Method  of  Charring  in  Metiers. 

A  metier  is,  in  tine,  a  lot  of  wood  piled  up  or  raised  up 
according  to  certain  rules  on  a  so-called  hearth,  a  place 
which  has  been  cleared  and  levelled  and  is  either  flat  or 
gently  sloping.  The  heap  of  wood  is  thatched  with  char- 
coal dust,  if  this  is  at  hand,  but  if  not,  with  dirt,  sawdust, 
and  the  like,  in  order  to  prevent  in  this  manner  the  admit- 
tance of  air,  for  otherwise  the  whole  would,  when  kindled, 
burn  to  ashes.  When  the  metier  has  been  thatched  it  is 
ignited  at  some  certain  point,  which  varies  in  situation 
according  to  the  construction  of  the  metier.  When  the 
fire  is  well  established,  the  place  of  igniting  is  carefully 
covered,  but  if  the  thatching  is  everywhere  perfectly  tight 
the  fire  will  soon  be  extinguished,  while  it  will  be  nourished 
more  or  less  lively  by  a  more  or  less  liberal  access  of  fresh 
air.  Sometimes  the  covering  is  so  thin  that  the  necessary 
air  can  pass  through,  but  more  commonly,  especially  in 
standing  metiers,  it  is  necessary  to  make  small  openings 
in  the  covering  for  the  air  to  pass  through.  Then  the 
draught  is  so  regulated  that  the  oxygen  entering  may 
be  just  sufficient  to  burn  what  wood  and  charcoal  is 
needed,  in  order  that  the  coaling  of  the  wood  may  pro- 


28  HAND-BOOK    FOE    CHARCOAL    BURNERS. 

gress  gradually  from  the  exterior  to  the  interior;  and  in 
order  that  the  development  of  gases  may  be  kept  steady  by 
a  well-regulated  temperature.  But  for  this  purpose  it  is 
necessary  to  allow  the  nitrogen  (constituting  about  three- 
fourths  of  the  air)  and  the  gaseous  products  of  charring 
(carburetted  hydrogen,  carbolic  acid,  carbonic  oxide,  tar, 
etc.)  to  escape,  and  therefore  openings  are  carefully  made 
here  and  there  in  the  covering.  During  the  whole  coaling 
process  the  draught  should  be  so  regulated  that  the  outside 
air  does  not  find  its  way  to  the  red-hot  charcoal,  for  in  that 
case  the  latter  is  consumed.  It  first  gradually  grows  porous 
and  spongy,  and  finally  goes  to  ashes.  But  we  must  not 
permit  the  smoke  to  pass  out  through  the  glowing  mass  of 
charcoal,  for,  as  has  already  been  stated,  when  the  watery 
steam  and  carbonic  acid  come  in  contact  with  glowing 
charcoal,  they  consume  it  in  course  of  time,  and  besides 
air  is  easily  mixed  with  it.  To  prevent  this  we  must  stop 
the  air-holes  with  a  shovel  in  that  part  of  the  meiler  in 
which  the  wood  is  already  coaled,  and  open  new  air-holes, 
but  always  near  where  the  coaling  process  is  going  on.  In 
this  manner  the  hot  charcoal  will  be  well  protected  by  the 
covering,  and  will  be  surrounded  by  gases  produced  by  the 
coaling  process  going  on  in  near  proximity  to  it,  and  con- 
taining no  free  oxygen.  By  all  these  means  the  charcoal 
that  is  cooling  will  be  tolerably  well  protected  from  con- 
sumption. The  fire  and  heat  progress  in  the  opposite 
direction  to  the  draught,  until  the  coaling  finally  ceases 
near  the  ground,  which  by  its  dampness  and  coolness  stops 
the  coaling,  and  makes  it  impossible  to  get  every  block  of 


HAND-BOOK   FOE    CHARCOAL    BURNERS. 


29 


wood  coaled ;  and  hence,  after  the  charring  is  complete, 
there  remains  not  only  thoroughly  charred  black  charcoal, 
but  also  imperfectly  carbonized  charcoal  in  the  form  of 
lignites  and  brands. 

1.  STANDING  MEILERS  OR  HEAPS  ON  HORIZONTAL  HEARTHS, 
WITH  CHIMNEY  AND  COVERING. 


FIG.  1. 

The  Preference  of  Old  Hearths. 

Since  standing  meilers  are  used  more  generally  than 
lying  meilers ,  standing  meilers •,  with  their  care,  will  be  first 
considered.  There  are  several  kinds  of  these,  which  must 
be  treated  separately,  and  we  will  begin  with  the  kind  most 
universally  used  in  Sweden,  namely,  the  standing  meiler  on 
a  horizontal  hearth,  with  chimney  and  wTood-covering. 

It  is  a  very  important  matter  in  all  methods  of  coaling  in 
meilers  to  have  the  hearth  or  bottom  dry,  solid,  and  free 
from  draught.  If  the  hearth  be  poor,  the  coaling  product 
will  be  poor  in  spite  of  the  best  care  and  attention  in  other 
respects.  Time  and  money  expended  in  making  a  good 


30  HAND-BOOK   FOR   CUARCOAL    BURNERS. 

hearth  is  a  capital  that  pays  a  large  interest.  According 
to  everybody's  experience  the  value  or  quality  of  the  hearth 
increases  every  time  it  is  used  for  coaling  purposes,  while 
a  newly  made  hearth,  though  it  may  be  prepared  with  the 
utmost  care,  may,  from  circumstances  that  are  not  so  easily 
determined,  not  only  while  new,  but  even  after  several  coal- 
ing processes,  prove  to  be  more  or  less  poor  and  destructive 
of  wood.  In  view  of  this  it  is  an  important  rule,  when 
one  has  succeeded  in  finding  a  good  hearth,  to  make  use  of 
this  as  long  as  possible,  even  though  the  wood  has  to  be 
hauled  from  a  distance,  increasing  the  expense  of  labor  and 
transport. 

Choice  and  Preparation  of  a  New  Hearth. 

When  a  new  hearth  -is  required,  as  dry  and  level  a  place 
as  may  be  should  be  sought  out,  if  possible  on  a  slight  ele- 
vation sloping  on  all  sides.  Low  places,  where  water  gathers 
or  springs  are  found,  should  be  carefully  avoided ;  likewise 
places  where  blueberry  bushes  grow  luxuriantly,  or  where 
bear  moss  and  white  moss  are  found  in  spots ;  for  these 
always  indicate  dampness.  Still  water  should  be  found 
accessible  for  extinguishing  the  charcoal,  and  in  such 
quantities  that  it  does  not  give  out  in  dry  seasons  of  the  year. 

The  place  should  be  so  selected  that  wood  several  years 
in  succession  may  easily  and  conveniently  be  brought  there ; 
the  place  should  also  be  accessible  for  wagons,  in  order 
that  the  charcoal  may  be  easily  hauled  away,  and  further- 
more there  should  be  a  dry  place  near  by,  sufficiently  large 
for  sheds  in  which  to  keep  the  charcoal  protected. 


HAND-BOOK   FOR   CHARCOAL   BURNERS.  31 

It  is  also  very  important  that  the  ground  selected  for  a 
new  hearth  should  be  uniformly  firm  and  solid.  For  if 
the  ground  is  softer  in  some  places  than  in  others,  and  more 
easily  penetrated  by  the  air,  then  the  coaling  will  neces- 
sarily progress  faster  over  these  soft  places  than  in  the 
other  parts  of  the  meiler*  and  the  charcoal  there  will  be 
consumed  or  become  loose  and  poor.  The  same  takes  place 
if  rocks  or  stones  protrude  from  the  ground,  as  draught  is 
generally  produced  around  them.  If  a  hearth  is  to  be 
made  in  such  a  place,  it  is  necessary  to  blast  away  or  in 
some  way  remove  these  rocks  and  stones,  at  least  half  a 
foot  deep,  and  then  carefully  fill  again  the  holes  and  ex- 
cavations with  the  same  kind  of  material  as  forms  the  rest 
of  the  hearth.  Stumps  and  roots  should  likewise  be  care- 
fully removed,  while  small  stones  evenly  distributed  over 
the  hearth  do  no  harm. 

A  very  loose  and  porous  hearth,  even  if  it  is  uniformly 
so,  for  instance  of  coarse  sand  or  gravel,  is  not  serviceable, 
since  the  draught  from  below  then  becomes  too  strong,  so 
that  the  temperature  becomes  altogether  too  high,  the  coal- 
ing process  gets  too  rapid,  and  the  charcoal  becomes  loose. 
Hence  such  ground  should  be  improved  by  covering  it 
with  a  firmer  and  tighter  substance — for  instance,  a  layer 
of  clay.  On  the  other  hand,  it  is  insisted  upon  that  the 
ground  must  not  be  too  hard  or  tight,  as  *is  the  case  with 
hard  clay ;  in  that  case  the  ground  should  be  spaded  up 
and  mixed  with  sand  or  dust.  For,  it  is  said,  a  too  solid 
hearth  retards  the  progress  of  coaling  too  much,  prevents  the 
ground  from  absorbing  the  moisture,  and  produces  a  large 


32  HANDBOOK   FOE   CHARCOAL   BUENEES. 

quantity  of  lignites  and  brands.  This  assertion  seems 
doubtful,  however ;  for  how  is  it  possible  to  manage  the 
draught  with  sufficient  exactness,  if  the  hearth  admits  air 
in  quantities  large  enough  to  have  any  perceptible  influence 
upon  the  progress  of  coaling  ?  When  the  coaling  process 
has  reached  the  bottom  in  the  centre  of  the  meiler,  what 
will  prevent  the  charcoal  from  burning  up,  if  air  penetrates 
the  ground  and  reaches  the  glowing  charcoal  ?  It  is  indeed 
difficult  to  understand  why  a  perfectly  air-tight  hearth 
should  not  be  the  best.  We  know  that  a  hearth  that  is 
good  in  the  beginning  improves  by  every  coaling  process, 
but  a  hearth  tight  of  itself,  when  it  has  been  drenched  and 
tightened  year  after  year  with  tar,  is  certainly  quite  im- 
penetrable to  air.  And  still  no  complaints  are  made  in 
regard  to  such  meilers  about  slow  progress,  brands,  water, 
etc. 

Even  tolerably  flat  stones,  if  they  do  not  contain  large 
cracks,  may  be  used  with  advantage  for  hearths,  but  they 
should  be  tightened  and  levelled  with  charcoal  dust  or 
loose  earth.  In  case  of  need,  rocky  ground  may  be  made 
serviceable  by  a  thick  layer  or  filling  of  carefully  packed 
charcoal  dust. 

Protecting  the  hearth  from  surface  water  should  never 
be  neglected,  but  it  is  especially  necessary  when  the  hearth 
is  situated  at  the"  foot  of  a  hill.  It  is  very  wrong  to  dig  a 
hearth  below  the  surface.  On  the  contrary,  it  should  al- 
ways lie  a  little  higher  than  the  surrounding  ground,  in  or- 
der that  both  the  rain-water  and  the  moisture  evaporating 
from  the  wood  and  condensing  may  be  drained  away. 


HAND-BOOK    FOR    CHARCOAL    BURNERS.  33 

The  draining  away  of  the  water,  especially  upon  very 
high  and  solid  ground,  is  facilitated  in  standing  meilers  by 
making  the  usually  round  hearths  not  perfectly  horizon- 
tal, but  raised  a  few  inches  at  the  centre  and  sloping  on 
the  sides.  It  is  a  general  rule  that  a  new  hearth  should  be 
prepared  some  time,  say  a  year,  before  it  is  used.  In  this 
way  it  has  a  better  chance  to  dry  and  settle,  and  the  uneven 
spots  and  cracks  produced  by  shrinking  may  be  filled  and 
levelled.  It  is  also  usual  to  bring  together,  on  the  newly 
prepared  hearth,  stumps,  limbs,  branches,  etc.,  into  aheap, 
which  is  covered  with  loose  earth  and  sod  and  then  ignited. 
This  earth,  mixed  with  ashes  and  tar-smoke,  falls  upon  the 
fresh  hearth  and  improves  it,  and  in  this  manner  we 
may  also  get  good  dust  for  covering  and  tightening  the 
metier. 

When  the  situation  is  such  that  the  use  of  the  wood  to 
good  advantage  makes  it  necessary  to  locate  the  hearth  on 
moss  or  in  a  swamp,  we  must,  first  of  all,  make  the  place 
dry  by  deep  ditches.  When  this  is  done  we  lay  first  brush 
or  straw  in  the  bottom,  upon  this  a  strong  and  tight  tier  of 
logs,  which  is  covered  two  feet  thick  with  dust  or  clay. 
But  on  such  hearths  no  coaling  must  be  done  in  the  fall, 
for  during  the  heavy  rains  the  water  may  rise  under  the 
hearth  and  produce  a  very  poor  coaling  of  the  wood. 

Frequently  it  is  necessary  to  locate  the  hearth  on  a  ?teep 
slope  of  a  hill.  In  spite  of  this,  the  hearth  is  to  be  made 
horizontal,  as  is  the  case  with  the  kind  of  standing  metiers 
of  which  we  are  now  speaking.  We  must  first  find  a  secure 
foundation  on  the  lower  side,  on  which  to  build  up  a  wall 


34-  HAND-BOOK   FOR   CHARCOAL    BURNERS. 

of  logs  to  the  necessary  height.  Upon  this  wall  we  then 
lay  a  floor  of  split  wood,  which  we  cover  with  bark  or 
moss.  Finally  the  whole  is  covered  a  foot  deep  with  sand 
or  clay,  or  still  better  with  a  mixture  of  both,  which  cover- 
ing must  be  well  packed.  Partly  on  account  of  sinking, 
and  partly  to  prevent  a  stronger  draught  from  the  lower 
side  of  the  hill,  the  edge  of  the  hearth  should  be  somewhat 
higher  on  this  side  than  on  the  other. 

Without  considering  the  far  greater  expense,  attempts  at 
producing  serviceable  hearths  in  this  manner  or  in  swamps 
and  on  moss  are  seldom  successful,  in  spite  of  all  possible 
care  and  exactness  in  doing  the  work,  hence  we  should  re- 
sort to  these  methods  only  when  it  is  absolutely  necessary. 

The  Care  and  Improvement  of  the  Hearth  after  Coaling. 

After  a  meiler  has  been  coaled  and  the  charcoal  re- 
moved, the  dust  remaining  on  the  hearth  should  be  shov- 
elled away  and  laid  in  a  heap  for  the  next  coaling.  This 
shovelling  away  should  be  done  immediately  after  remov- 
ing the  charcoal,  or  at  least  so  early  in  the  spring  that  the 
hearth  may  get  time  to  dry  well.  But  we  must  take  good 
care  not  to  break  up  the  crust  of  tar  in  the  bottom  of  the 
hearth,  as  it  is  this  very  crust,  growing  more  solid  and  tight 
with  each  coaling  process,  that,  more  than  anything  else, 
causes  coaling  on  old  hearths  to  be  better  than  on  new 
ones.  In  this  work  of  cleaning,  the  hearth  should  be  care- 
fully examined,  especially  if,  on  account  of  the  last  coaling 
operation  being  poor,  there  is  reason  to  suppose  that  it  is  in 
any  place  poor  or  not  tight.  A  place  where  there  is  draught, 


HAND-BOOK   FOR  CHARCOAL    BURNERS.  35 

even  though  it  was  not  found  in  removing  the  charcoal, 
although  it  is  usually  indicated  by  loose  and  dusty  char- 
coal, which  is  always  found  in  such  parts  of  the  meiler, 
may  be  easily  discovered,  when  shovelling  out  the  dust,  by 
the  ease  with  which  the  shovel  goes  through  it  and  by  the 
ashes  found  there.  We  then  dig  up  the  defective  place 
1£  to  2  feet  deep,  then  lay  down  either  thin,  flat  stones  or 
spruce  or  birch  bark.  Upon  this  we  fill  in  with  clay,  sand, 
or  loose  earth,  and  finally  with  charcoal  dust,  packing  it  all 
well  down.  As  a  place  patched  in  this  way  settles  some- 
what, it  should  be  made  something  higher  than  the  rest  of 
the  hearth.  When  a  hearth  is  shovelled  out  it  is  necessary 
to  clean  the  dust  from  roots,  turf,  fibrous  substances,  etc., 
since  such  things  make  the  dust  leaky  when  it  is  to  be 
used  next  time. 

The  Felling,  Seasoning,   and  Sorting  of   Wood  to   be 

Coaled. 

Wood  for  making  charcoal  is  taken  partly  from  trees 
blown  down  by  the  wind  and  partly  from  trees  seasoned 
while  standing.  In  several  districts  it  is  common  to  strip 
the  sound  tree,  which  is  to  be  used  a  few  years  afterwards 
for  charcoal,  two  to  three  feet  above  the  ground,  while  the 
tree  is  in  a  healthy  growing  state.  By  this  treatment, 
which  is  called  girdling,  the  tree  gradually  seasons,  and 
hence  trees  so  treated  are  in  every  respect  like  seasoned 
wood.  Since  dried  trees,  especially  if  they  have  begun  to 
decay,  do  not  dry  more  by  being  felled  and  stripped  of 
their  branches,  but  rather  have  a  tendency  to  absorb  moist- 


36  HAND-BOOK   FOR   CHARCOAL   BURNERS. 

lire,  they  should  be  left  standing  as  near  the  time  of  coal- 
ing as  possible.  But  quite  the  opposite  is  the  case  with 
timber  that  is  still  healthy  and  growing.  We  have  stated 
before  how  we  are  to  treat  this  kind  of  timber,  namely, 
that  it  should  be  felled  in  winter  between  November  and 
March  ;  that,  after  cutting  the  limbs  off,  the  bark  should  be 
stripped  off  in  strips  ;  that  the  butt- ends  of  the  stems  turn- 
ing south  should  be  raised  from  the  ground,  etc.  Some 
claim  that  the  felled  green  meiler-wood  should  lie  and 
season  two  summers  before  it  is  put  into  the  meiler.  But 
it  cannot  be  denied  that  if  the  felling  and  drying  of  the 
wood  receives  proper  care  it  will  season  sufficiently  in  one 
summer  to  be  coaled  in  the  fall  of  the  same  year.  It  is 
also  known  that  when  trees  lie  too  long  in  the  woods,  ex- 
posed to  all  kinds  of  weather,  the  outside  immature  wood 
grows  blue,  which  is  a  sign  that  it  has  begun  to  deteriorate, 
and  it  is  absolutely  certain  that  spoiled  wood  produces 
poor  charcoal.  Also  rafted  wood,  taken  up  in  the  spring, 
dries  sufficiently  to  be  coaled  during  the  fall  of  the  same 
year,  if  it  is  taken  on  dry  ground  and  piled  up  in  heaps 
with  considerable  open  space,  so  that  the  air  may  circulate 
freely  around  each  log. 

That,  wood  felled  in  winter  is  more  solid  and  compact 
we  already  know,  but  this  time  of  felling  should  be  insisted 
upon  also  for  another  reason.  Wood  which  is  felled 
especially  in  sap-time,  and  also  in  the  summer  and  fall, 
soon  sours  and  the  exterior  part  turns  blue  ;  thus  it  easily 
becomes  spoiled,  and  produces  for  this  reason  an  inferior 
quality  of  charcoal.  But  this  is  not  all.  This  manner  of 


HAND-BOOK   FOR   CHARCOAL    BURNERS.  37 

proceeding  may  also  cause  a  great  destruction  of  the  tim- 
ber still  growing,  since  a  large  number  of  insects  settle  in 
the  decaying  wood  and  multiply  to  an  incredible  extent. 

Still  another  advantage  in  felling  during  winter  is  that 
the  bark  is  saved,  which  also  produces  charcoal,  while  the 
trees  felled  in  sap-time  lose  their  bark  if  not  sooner  at  least 
when  the  charcoal  is  removed  from  the  meiler.  If,  from 
some  cause  or  other,  one  is  obliged  to  fell  the  trees  after  the 
close  of  winter,  they  should  be  left  with  the  limbs  on 
until  the  pine-needles  (or  foliage)  dry  and  fall  off.  Then 
the  limbs  are  cut  off,  and  the  wood  is  treated  as  if  it  had 
been  felled  in  winter. 

An  exception  to  what  has  been  said  about  the  advantage 
of  felling  trees  in  winter  exists  in  the  treatment  of  so- 
called  waste  wood.  This  is  generally  obtained  from  under- 
brush, in  which  but  little  sap  is  in  circulation,  and  which 
may  j  ust  as  well  be  cut  down  in  summer  time.  Waste 
wood  generally  dries  slowly,  and  therefore  it  should  be 
felled  a  year  beforehand,  and  immediately  after  felling  it 
should  be  brought  into  a  sunny  place  to  be  piled  up  in 
open  or  airy  heaps.  But  this  rule  must  not  be  taken 
literally.  The  waste  wood,  which  in  its  texture,  etc.,  is 
very  much  like  common  wood  for  coaling,  should  of  course 
be  treated  like  the  latter. 

Some  persons  say  that  half-seasoned  wood  is  better  for 
coaling,  and  that  such  wood  gives  better  charcoal,  though 
in  a  somewhat  smaller  quantity,  than  perfectly  dry  wood. 
Now  it  is  true  that  perfectly  dry  wood  requires  greater 
skill  and  attention  from  the  collier,  in  order  that  the  tern- 


38  HAND-BOOK    FOR   CHARCOAL    BURNERS. 

peratnre  in  the  meiler  may  not  become  too  high,  and  the 
charcoal  in  consequence  loose  and  weak ;  but  if  the  work 
is  done  properly,  it  is  absolutely  certain  that  the  driest 
wood  gives  the  most  and  the  best  charcoal. 

It  will  be  shown,  farther  on,  that,  in  the  coaling  of  a 
meiler,  certain  parts  of  it  are  exposed  to  a  greater  and 
more  persistent  degree  of  heat,  and  that  therefore  coarser 
and  less  perfectly  seasoned  wood,  and  also  more  solid 
kinds  of  wood,  may  be  used  in  these  parts  of  the  meiler 
without  any  disadvantage.  On  the  other  hand,  to  put  up 
together  in  a  meiler  large  and  small  wood  of  different 
qualities,  without  being  sorted,  is  always  a  great  mistake  ; 
hence  it  is  of  importance  to  sort  the  wood  according  to 
size,  degree  of  dryness,  etc. 

Very  thick  blocks  should  be  split,  and  likewise  hollow 
wood. 

It  is  very  important  to  cut  the  limbs  off  close  to  the 
stem  for  knots  remaining,  make  the  raising  of  the  meiler 
difficult  and  produce  openings  in  it,  which  should  be  care- 
fully avoided. 

Good  care  of  the  timber  requires  that  the  trees  should 
be  cut  as  near  the  ground  as  possible,  that  at  least  all 
large  branches  be  burnt  up  and  used  in  the  meiler,  and 
that  the  saw  be  substituted  for  the  axe,  wherever  possible. 

Rafting  and  hauling  is  made  easier  by  cutting  up  the 
trees  beforehand  in  the  lengths  that  the  wood  is  to  have 
in  the  meiler,  and  the  usual  length  of  the  wood  in  the  kind 
of  standing  meiler  s,  of  which  we  are  now  speaking,  is  8 
to  10  feet,  or  on  an  average  9  feet. 


HAND-BOOK   FOE   CHARCOAL    BURNERS.  39 

The  Staking  out  of  the  Hearth  ;  Making  of  Chimney  / 
Raising  of  the  Wood. 

"When  the  hearth  has  been  made,  the  billets  hauled  and 
sorted,  the  next  thing  is  to  prepare  the  hearth  for  the 
building  of  the  meiler,  which  is  done  in  the  following  man- 
ner :  When  it  has  been  decided  how  large  a  radius  the 
meiler  is  to  have,  which  radius  of  an  average  sized  standing 
meiler  is  about  16  to  IT  feet,  then  its  limits  are  staked  out 
at  thejfootf,  as  the  lower  exterior  part  of  the  meiler  is  usually 
called,  by  fastening  one  end  of  a  rope  or  pole  of  the  length 
of  the  radius  of  the  hearth,  to  the  centre  of  the  hearth  and 
then  drawing  the  other  end  around.  The  free  end  of  the 
pole  or  rope  will  now  describe  the  circumference  of  a  cir- 
cle reaching  precisely  to  the  outside  limit  of  the  foot  of  the 
meiler,  which  is  marked  out  by  small  stakes  three  or  four 
feet  apart.  Then  the  hearth  within  this  circumference  is  lev- 
elled, so  that  it  becomes  perfectly  level  all  the  way  around, 
and  when  this  is  done  we  give  this  circular  space  a  gradual 
slope  from  the  centre  to  the  circumference,  so  that  the  centre 
of  the  hearth  may  be  4  to  10  inches  higher  than  the  outside 
edge.  This  gradual  slope  facilitates,  as  has  been  shown,  the 
running  off  of  water,  but  it  is  also  believed  that  the  coaling 
especially  of  the  exterior  parts  of  the  meiler  to  its  foot,  is 
assisted  on  account  of  the  general  rule,  that  coaling  in  the 
opposite  direction  to  the  draught  progresses  more  rapidly 
down  a  slope  than  up  it  or  along  a  horizontal  hearth.  The 
height  of  the  centre  is  determined  by  the  nature  of  the 
hearth  and  wood.  If  the  ground  is  loose  and  dry,  and  the 


40  HAND-BOOK   FOR    CHARCOAL    BURNERS. 

material  to  be  coaled  consists  of  well-seasoned  coniferous 
wood,  the  hearth  may  be  made  almost  level ;  while  the 
greatest  rise  is  required  when  the  hearth  is  very  solid  and 
tight,  and  the  wood  is  either  very  sour  or  is  taken  from 
foliferous  trees. 

In  the  next  place  a  perpendicular  chimney  is  put  up  in 
the  centre  of  the  hearth  thus  prepared.  This  may  be  done 
in  various  ways.  One  way  is  to  put  down  firmly  into  the 
ground  3  or  4  straight  stiff  poles  fastened  well  together  at 
the  top  with  a  willow,  so  that  inside  of  them  is  formed  a 
triangular  or  quadrangular  space,  each  side  measuring  8  to 
10  inches.  Another  way,  as  represented  in  Fig.  2,  is  to 
raise  a  log  7  to  8  inches  in  diameter  perpendicularly,  and 
to  secure  it  in  position  by  3  or  4  braces.  Whether  this  log 
is  let  down  into  the  ground  half  a  foot  or  stands  upon  the 
surface  makes  no  difference.  The  main  point  is  that  it 
shall  stand  secure.  Into  this  log  we  drive,  two  or  three 
feet  from  its  top,  two  horizontal  wedges,  slanting  towards 
each  other,  and  so  long  that  by  placing  poles  outside  of 
these  we  get  a  triangular  opening  with  sides  of  7  to  8  inches, 
around  which  the  billets  are  raised.  In  whatever  way  the 
chimney  is  made,  it  is  of  importance  that  the  poles  be  of 
the  same  height  as  the  meiler. 

Then  is  placed  in  the  chimney  a  perfectly  straight  pole, 
called  the  guide-pole,  which  serves  as  a  guide  in  raising  the 
billets,  in  order  that  the  latter  may  not  lean  to  either  side, 
and  in  order  that  this  pole  may  be  conveniently  seen  every- 
where it  should  be  at  least  6  to  8  feet  longer  than  the  meiler- 
wood. 


HAND-BOOK   FOR   CHARCOAL    BURNERS. 


Now  we  begin  to  raise  the  wood  around  this  chimney 
formed  in  one  way  or  the  other.  In  doing  this  we  should 
select  the  finest  and  driest  wood  first,  to  facilitate  the 
kindling  of  the  meiler. 

It  is  of  great  importance  to  raise  the  wood  as  closely  and 
as  uniformly  as  possible,  for  other- 
wise it  may  easily  happen,  to  great 
disadvantage  to  the  coaling,  that 
the  fire  burns  faster  in  one  direc- 
tion than  in  another.  The  wood 
is  set  up  almost  perpendicularly, 
leaning  very  slightly  towards  the 
chimney,  only  so  much  that  the  up- 
per ends  of  the  wood  may  rest  on  the 
chimney.  By  means  of  the  guide- 
pole,  we  can  see  that  the  wood  does 
not  lean  to  either  side  of  the  chim- 
ney, for  then  the  whole  meiler 
might  tumble  down,  or  get  twisted 
out  of  shape  in  coaling. 

When  the  interior  part  of  the 
meiler  has  been  formed,  we  con- 
tinue to  place  layer  after  layer 
around  this  mainly  in  the  same 
manner,  but  gradually  using  larger 

wood,  until  the  meiler  has  a  radius  of  4  to  5  feet,  at  which 
distance  from  the  centre  the  highest  or  at  least  the 
most  persistent  temperature  is  developed  during  the  coal- 
ing process,  wherefore  this  is  the  best  place  to  put  the 


FlG 


42  HAND-BOOK   FOR   CHARCOAL    BURNERS. 

largest  and  sourest  wood,  as  also  wood  from  birch  and  other 
kinds  of  foltferous  trees,  if  it  be  necessary  to  mix  them. 
Wood  that  is  slowly  charred  may  also  be  put  in  the  other 
parts  of  the  m.eiler  in  such  places,  namely,  as  experience 
has  proved  consumption  to  take  place  in  an  excessive 
degree,  on  account  of  untight  ground  or  other  causes, 
although  it  is  undoubtedly  far  better  to  look  up  the 
causes  of  such  irregularities  in  the  coaling  process  and 
remedy  them  beforehand  by  carefully  tightening  and 
levelling  the  hearth,  etc. 

Still,  to  raise  several  layers  of  large  wood  in  the  meiler 
would  make  it  altogether  too  open  and  difficult  to  manage, 
and  hence  the  intervening  spaces  between  the  large  blocks 
of  wood  should  be  carefully  filled  with  fine  wood  and  twigs. 
By  always  turning  the  butt-ends  of  the  wood  down  to  the 
ground,  the  upper  ends  will,  as  the  raising  gradually  pro- 
gresses from  the  centre  of  the  meiler,  assume  a  greater 
slope  inward.  But  it  has  been  found  that  this  slope  in- 
ward, far  from  being  injurious,  on  the  contrary  is  advan- 
tageous and  in  some  cases  may  be  necessary,  for  in  this  way 
it  is  easier  for  the  meiler  to  settle  and  pack  as  the  coaling 
and  shrinking  of  the  wood  progress  ;  and  besides,  the  cov- 
ering of  charcoal  dust  can  only  in  this  manner  be  kept  on 
the  sides  of  the  meiler.  It  is  also  always  necessary  when 
the  wood  does  not  slope  much,  or  when  the  circumference 
of  the  meiler  is  very  great,  to  pull  the  wood  out  a  little  at 
the  lower  end,  as  it  is  upon  the  whole  beneficial  to  stop  up 
the  vacant  places  near  the  hearth  with  twigs  and  other 
short  and  small  wood.  The  requisite  slope  may  also  be  ob- 


HAND-BOOK    FOR   CEIABCOAL   BURNERS.  43 

tained,  though  at  the  expense  of  the  tightness  of  the  wood 
near  the  chimney,  by  beginning  to  raise  the  meiler  with 
very  short  wood  and  gradually  using  longer  wood  in  each 
successive  layer.  Generally  speaking,  the  outside  layer 
should  have  a  slope  of  60°,  or  in  other  words,  the  slope 
should  be  such  that  a  man  placing  himself  close  to  the  foot 
of  the  meiler  can  reach  the  wood  with  the  ends  of  his 
fingers,  when  stretching  his  arm  out  toward  the  meiler. 
When  the  weather  is  dry  and  the  covering  of  charcoal  is 
also  dry,  the  slope  should  be  greater  than  in  damp  weather ; 
likewise  the  slope  must  be  greater,  if  we  do  not  use  slabs, 
of  which  more  will  be  said  below. 

In  the  same  manner  as  the  innermost  layers,  the  outer- 
most ones  should  be  made  from  smaller,  drier,  and  more 
easily  coaled  wood.  The  coaling  heat  is  neither  so  great 
nor  persistent  as  further  into  the  meiler. 

Sometimes  it  is  customary  before  raising  the  wood  to 
place  on  the  hearth  poles,  several  inches  in  diameter, 
which  shoot  out  like  rays  from  the  centre,  and  which  are 
gradually  drawn  back  as  the  raising  of  the  wood  pro- 
gresses from  the  centre  to  the  circumference.  By  raising 
the  wood  around  these  poles  canals  are  formed  between 
the  chimney  and  the  outside  of  the  mailer,  which  canals 
are  at  their  mouths  about  3  or  4  feet  apart.  The  ad- 
vantage of  this  arrangement  is  claimed  to  be,  that  the 
openings  made  at  the  foot  of  the  meiler  opposite  such 
canals,  will  be  more  active  than  they  would  be  otherwise, 
and  for  this  reason  the  progress  of  the  coaling  will  be 
more  easily  controlled.  Against  this  method  may  be 


44  HAND-BOOK   FOE   CHARCOAL   BURNERS. 

urged  the  objection,  that  we  obtain  canals  not  only  out 
along  the  hearth  of  the  meiler,  which  might  be  desirable, 
but  we  also  get  a  series  of  open  spaces  narrowing  up- 
ward like  wedges,  which  might  do  harm  by  permitting 
the  covering  of  charcoal  dust  to  fall  through,  and  be  in- 
jurious in  other  ways.  It  would  be  better  and  safer  un- 
doubtedly to  lay  along  the  hearth  symmetrically  small 
three-sided  canals  by  fastening  together  at  right  angles 
two  boards  or  split  blocks  of  wood.  These  canals  should 
have  their  outlets  in  the  chimney,  and  provision  should 
be  made  for  opening  and  closing  them  at  pleasure  at 
various  distances  from  the  chimney.  It  is  apparent  that 
the  wood  could  be  raised  just  as  well  over  these  canals  as 
beside  them. 

Putting  on  the  Covering. 

When  the  meiler  in  the  manner  described  has  received 
its  proper  diameter  and  slope,  and  the  outside  layer  has 
been  most  carefully  tightened  and  levelled  by  small  wood 
of  two  to  three  inches  in  diameter,  twigs,  finely  split 
wood,  etc.,  then  all  the  tops  and  ends  of  the  wood  pro- 
truding are  cut  off,  and  all  the  openings  and  holes  that 
can  be  found  are  closed  with  twigs  and  other  small  wood. 
The  purpose  of  this  is  to  form  an  under-layer  as  smooth 
and  tight  as  may  be  for  the  upper  part  or  covering  of  the 
meiler.  This  covering  may  be  made  high  or  low,  and  we 
distinguish  between  whole-covering  and  half -covering. 
Whole-covering,  when  the  wood  is  raised  in  a  half-lying 
position  over  the  wood  beneath,  and  is  half  as  long  as  the 


HAND-BOOK   FOR   CHARCOAL   BURNERS.  45 

latter.  Half-covering,  when  the  wood  used  is  such  as  we 
get  by  cutting  meiler-wood  twice.  We  may  also  use  still 
shorter  wood,  twigs,  etc.,  since  in  making  the  covering  we 
do  not  look  so  much  to  increasing  the  size  of  the  meiler 
and  quantity  of  charcoal,  as  to  obtaining  a  pretty  tight 
and  solid  under-layer  for  the  exterior  covering,  with 
small  branches,  charcoal  dust,  etc.,  A  high  covering  may 
also  in  some  cases  be  of  disadvantage,  as  when  the  meiler 
is  very  much  exposed  to  stormy  weather,  since  it  becomes 
more  difficult  to  manage  a  high  meiler  than  a  low  one. 
But  whether  we  have  a  high  or  low  covering,  only  small 
wood  (finely  split  wood  if  necessary)  and  twigs  should  be 
used,  since  the  heat  in  this  part  of  the  meiler  is  not  so 
high  and  persistent,  and  the  charcoal  dust  may  easily  fall 
through  among  the  billets  if  the  wood  covering  is  coarse, 
which  always  prevents  more  or  less  the  perfect  coaling  of 
the  wood.  If  we  have  brands  from  a  previous  coaling, 
then  these  properly  split  form  a  good  mixture  with  the 
other  covering  wood.  It  is  of  no  special  importance  to 
make  this  wood  of  any  fixed  length.  This  is  very  seldom 
done,  for  the  covering  usually  consists  of  twigs  and 
crooked  wood  ;  but  a  skilled  collier  may,  even  with  wood 
of  unlike  length,  produce  a  good  covering,  and  give  the 
meiler  a  well-rounded  form. 

In  making  the  cover,  we  begin  at  the  centre  and  raise 
the  first  layer  of  wood  almost  vertically  against  the  above- 
mentioned  poles  forming  the  chimney,  but  afterwards, 
the  farther  we  get  away  from  the  centre,  the  more  we 
slope  the  layers  inward,  so  that  finally  they  lie  almost 


46  HAND-BOOK   FOR   CHARCOAL   BURNERS. 

horizontally  at  the  brow  of  the  metier.  Finally  the  cover- 
ing is  made  smooth  so  that  it  gets  the  properly  rounded 
form,  solidity,  and  tightness. 

If  there  is  no  support  for  lengthening  the  chimney 
above  the  under-wood,  the  beginning  of  one  is  made  by 
laying  very  short  wood  somewhat  aslant  around  the  chim- 
ney, and  with  the  ends  toward  its  upper  edge.  Upon  this 
first  layer  of  wood  we  then  put  somewhat  longer  wood, 
and  thus  continue  to  increase  the  length  of  the  wood,  un- 
til the  chimney  has  got  the  acquired  length,  or,  in  other 
words,  the  covering  has  obtained  its  proper  height ;  after 
which  the  additional  covering  is  put  on  in  the  usual  man- 
ner. 

It  is  important  in  making  the  covering  not  to  use  too 
large,  too  long,  or  too  green  wood.  Large  wood  permits 
the  charcoal  dust  to  fall  through ;  very  long  wood  pre- 
vents the  even  settling  of  the  metier  during  coaling; 
green,  or  long  wood,  interferes  materially  with  the  easy 
and  rapid  cooling  of  the  charcoal. 

In  case  other  materials  are  wanting,  brush  woodmay 
be  used  also  for  the  first  layer  of  covering.  This  is  cut 
into  here  and  there  with  the  axe  in  order  that  it  may  fall 
closer  to  the  meiler-woocl. 

Covering  the  Metier  with  Brushwood. 

"When  the  meiler  is  finished  with  respect  to  wood,  it  is 
next  covered  with  some  material  that  will  prevent  the 
covering  of  charcoal  dust,  to  be  put  on,  from  falling 
down.  Usually  spruce  brushwood  is  used  for  this  pur- 


HAND-BOOK   FOR   CHARCOAL    BURNERS.  47 

pose,  but  if  it  cannot  be  had,  moss  is  substituted.  Turf, 
dry  leaves,  heath,  straw,  etc.,  may  also  be  used.  Spruce 
brushwood  is  most  serviceable  when  the  wood  is  large 
and  green.  The  operation  begins  at  the  foot  of  the  mei- 
ler,  and  proceeds  from  there  over  the  brow  to  the  top  of 
the  covering,  and  is  done  in  such  a  manner  that  the  butt- 
ends  of  the  branches  are  placed  in  between  the  wood,  so 
that  the  brushwood  will  hang  down  on  the  sides  of  the 
meiler.  Between  the  foot  and  the  brow  it  is  sufficient  to 
make  this  covering  4  to  5  inches  thick.  The  finest  and 
closest  brushwood  should  "be  put  just  above  the  brow, 
and  there  they  should  be  laid  so  thick  that  the  wood  is 
not  felt  when  walking  on  the  covering;  but,  on  the  con- 
trary, the  brushwood  springs  under  the  feet.  When 
coaling  in  sandy  places  where  the  charcoal  dust  is  drier 
and  finer,  and  therefore  has  more  tendency  to  fall  down, 
it  is  best  to  thatch  the  covering  with  moss.  Yet  on  the 
sides  it  is  difficult  to  get  anything  but  spruce  brushwood 
to  stay.  When  we  thatch  with  moss,  old  brushwood  and 
dry  twigs  cut  into  pieces  should  be  laid  under,  for  other- 
wise it  happens  that  the  upper  part  of  the  wood  remains 
more  or  less  uncoaled.  Thick  turf,  especially  if  the  soil 
contain  clay,  makes  a  much  too  close  covering ;  hence 
the  turf  should  be  cut  quite  thin,  so  that  it  consists  almost 
exclusively  of  the  sod.  Thatching  with  the  materials 
above  mentioned,  excepting  spruce  brushwood  and  sod, 
should  be  made  5  to  6  inches  thick.  Upon  the  whole, 
the  more  uneven  and  full  of  holes  the  meiler  is,  the  closer 
the  thatching  should  be ;  and,  vice  versa,  the  better  the 


48  HAND-BOOK   FOR   CHARCOAL    BURNERS. 

meiler  is  tightened  with  small  wood,  the  less  care  is  re- 
quired in  putting  on  the  brushwood,  or  other  material 
for  thatching. 

In  case,  as  has  been  mentioned  above,  canals  are  made 
from  the  chimney  to  the  periphery  of  the  meiler,  by  lay- 
ing poles  like  rays  on  the  hearth,  which  are  not  taken 
away  before  the  canals  are  to  be  opened  at  the  foot,  it  is 
necessary  to  prevent,  in  some  convenient  way,  the  char- 
coal dust  from  falling  into  the  canals  during  the  coaling 
process. 

Covering  the  Mueller  with  Charcoal  Dust. 

The  meiler  should  be  covered  with  charcoal  dust  imme- 
diately after  it  has  been  thatched  with  the  wood  and  brush- 
wood covering  before  mentioned.  For  this  purpose  old 
charcoal  dust  is  the  most  serviceable ;  but  if  this  is  not  to 
be  had,  as  is  the  case  with  new  hearths,  charcoal  dust 
should  be  provided  at  least  for  the  covering  and  for  the 
rest  of  the  meiler.  We  may  then  use  some  other  material 
which  will  pack  nicely,  but  at  the  same  time  permit,  as 
the  charcoal  dust  does,  the  steam  and  gases  developed  in 
the  meiler  to  escape.  A  mixture  of  loam,  light  clay,  and 
sand  is  best.  Clay  unmixed  burns  together  and  hardens 
into  a  crust  over  the  meiler  /  unmixed  coarse  sand  is  too 
open  and  produces  too  much  heat,  while  fine  sand  is  in 
the  beginning  too  tight,  and  after  it  is  heated  it  easily  runs 
through  the  inside  covering.  By  burning  and  smoking 
in  the  manner  heretofore  described,  loose  earth  may  be 
improved,  but  care  still  demands  that  on  a  new  hearth. 


HAND-BOOK   FOR    CHARCOAL    BURNERS.  49 

with  new  charcoal  dust  or  other  material  for  covering,  the 
first  meiler  should  be  made  smaller,  since  it  has  been  cal- 
culated that  a  loss  of  charcoal  of  at  least  8  to  10  per  cent, 
cannot  be  avoided.  In  the  second  mailer,  it  is  possible  to 
reduce  this  loss  to  only  half  as  much,  and  in  the  third  one 
we  may  regard  the  hearth  and  charcoal  dust  as  perfectly 
reliable.  Old  hearths  used  continually  during  the  whole 
summer  acquire,  it  is  true,  an  excellent  quality  and  give  a 
large  quantity  of  charcoal,  but  the  charcoal  dust  soon  be- 
comes quite  light  and  dry,  and  also  gets  mixed  with  fine 
charcoal.  Under  such  a  covering  of  dust,  which  is  easily 
ignited  in  one  part  of  the  meiler,  while  it  runs  down  and 
is  wasted  in  another,  good  and  strong  charcoal  cannot  be 
produced.  At  every  removal  of  the  charcoal  this  dust 
should  therefore  be  sifted,  dampened  freely  with  water, 
and  be  mixed  with  sand. 

Whether  the  dust  is  put  on  the  covering  before  or  after 
it  is  put  on  the  sides  of  the  meiler  is  of  little  importance, 
and  both  methods  are  used.  Some  preference,  however, 
may  be  given  to  the  first  method,  since  the  covering  ought 
to  have  the  best  and  cleanest  dust,  and  the  work  is  facili- 
tated by  putting  the  dust  on  the  highest  part  of  the  meiler 
first.  The  layer  may  differ  very  much  in  thickness.  It 
may  be  from  4  to  8  or  10  inches,  depending  on  the  quality 
of  the  wood,  hearth,  and  dust,  as  well  as  on  the  season  of 
the  year  when  the  coaling  is  done.  Wood  from  foliferous 
trees  and  green  wood  in  general  takes  less  dust  than  dry 
wood  of  coniferous  trees  a^d  a  looser  hearth.  In  winter, 

when  the  weather  is  dry  and  clear,  we  use  more  dust  than 
3 


50  HAND-BOOK   FOR   CHARCOAL    BURNERS. 

in  summer  or  fall,  when  the  weather  is  rainy  or  foggy. 
Dust  mixed  with  fine  charcoal  is  put  on  more  freely  than 
heavy  and  sandy  dust.  Above  the  brow  of  the  meiler,  and 
on  that  side  where  the  air  circulates  most  freely,  the  thick- 
ness of  the  dust  should  not  as  a  rule  be  less  than  seven  to 
eight  inches.  If  the  coaling  is  done  in  a  season  of  the 
year  when  there  is  no  danger  of  frost,  it  is  well  to  have 
a  thinner  layer  of  dust  during  the  beginning  of  the  coaling 
process,  as  the  steam  wrill  then  escape  more  easily,  and 
the  upper  part  of  the  meiler  coal  more  rapidly,  and  when 
the  upper  part  of  the  meiler  has  been  coaled  put  on  more 
dust.  On  the  other  hand,  late  in  the  fall  it  is  advisable 
not  only  to  thoroughly  complete  the  dust  covering  before 
igniting,  but  also  to  have  conveniently  at  hand  a  suffi- 
cient quantity  of  prepared  dust  to  use  if  necessary. 

If  the  weather  is  dry  and  the  meiler  slopes  a  great  deal, 
studding  should  be  put  up  on  the  sides,  of  slabs,  men- 
tioned before,  to  sustain  and  keep  the  dust  in  its  place. 
Split  wood  six  to  eight  feet  long  and  four  to  five  inches 
thick,  somewhat  crooked  if  possible,  is  very  serviceable 
for  this  purpose.  In  the  middle  of  each  of  these  slabs  on 
the  round  side,  a  cross-piece  is  let  into  the  slab  long 
enough  to  reach  the  ground.  These  slabs  are  put  hori- 
zontally round  about  the  meiler  as  near  the  brow  as  possi- 
ble, so  that  we  will  not  have  to  put  up  a  second  tier  above 
the  first  one.  It  is  always  difficult  to  keep  the  dust  suf- 
ficiently tight  under  these  slabs,  wherefore  the  dust 
should  be  packed  with  the  utmost  care,  before  they  are 
put  on. 


HAND-BOOK   FOR    CHARCOAL    BURNERS.  51 

When  the  dust  is  put  on  we  examine  carefully  whether 
it  has  the  proper  thickness  everywhere.  It  should  be 
levelled  down  or  filled  up  as  the  case  may  require,  and  be 
packed  around  the  sides  and  the  brow,  which  is  usually 
done  with  the  guide-pole,  which  is  taken  out  of  the  meiler 
when  the  billets  are  raised.  A  meiler  raised  in  the  fall 
should  be  covered  immediately,  thus  preventing  rain  and 
dampness  from  penetrating  the  wood  and  running  down 
to  the  hearth.  On  the  other  hand,  it  is  profitable  to  let 
meilers  raised  in  the  spring  or  summer  stand  uncovered 
until  they  are  to  be  coaled,  thereby  prolonging  the  time 
for  seasoning  the  wood.  Still  they  should  be  covered 
before  fall. 

Igniting  the  Meiler. 

When  the  charcoal  dust  has  been  put  on,  the  meiler  is 
ready  to  be  ignited.  This  should  be  done  in  still  weather 
and  early  in  the  morning,  in  order  that  we  may  have  day- 
light for  the  first  hours,  in  which  the  work  is  important 
and  requires  close  attention.  The  fire  may  be  made  with 
charcoal  or  wood,  but  charcoal  is  better,  since  it  is  more 
certain  to  ignite  and  gives  more  heat,  by  which  the  drying 
of  the  hearth  and  the  centre  wood  is  greatly  facilitated. 
The  fire  is  kindled  by  making  two  or  three  pieces  of 
charcoal  red  hot,  then  letting  them  down  the  chimney, 
after  which  we  fill  about  one-third  of  the  chimney  with 
charcoal.  It  should  be  packed  down  well  by  t\\e  filling- 
rod,  which  takes  its  name  from  this  operation,  and  when 
the  charcoal  is  well  ignited,  the  upper  part  of  the  chimney 


52  HAND-BOOK    FOE    CEIARCOAL    BURNERS. 

is  filled  in  the  same  manner ;  and  when  all  the  filling  is 
heated  to  a  red  glow,  so  that  we  may  be  sure  the  fire 
will  not  go  out,  we  fill  up  again,  if  necessary,  with  wrell 
packed  charcoal  clear  to  the  top,  which  is  then  closed  np. 

Igniting  with  wood  is  done  by  letting  down  to  the 
bottom  a  large  burning  torch,  and  then  we  fill  up  with 
finely  split  dry  wood,  or  brands.  When  the  chimney  is 
full  and  the  flames  begin  to  rise  above  the  top  of  the 
chimney,  we  put  in  more  wood,  which  is  carefully  packed 
down,  and  when  two  or  three  chimney  fills  have  thus  been 
consumed  the  vent  is  covered,  after  packing  down  as 
much  wood  as  possible,  and  we  may  now  be  sure  that  the 
fire  will  not  go  out. 

But  whenever  the  combustion  requires  air  and  draught, 
4  to  8  small  openings  at  the  foot  are  made  with  a  rod  at 
the  same  time  as  the  meiler  is  ignited.  The  number  of 
these  openings  will  depend  upon  the  size  of  the  meiler. 
Through  these  openings  the  air  will  be  drawn  into  the 
chimney,  so  that  a  more  or  less  strong  draught  will  be 
produced  from  the  foot  of  the  mailer  up  through  the 
chimney.  The  strength  of  the  draught  will  depend  upon 
the  size  and  number  of  these  openings  and  upon  the  qual- 
ity of  the  charcoal  or  wood  used  for  fuel  in  the  chimney. 

It  is  of  importance  that  the  kindling  heat  be  kept  nei- 
ther too  low  nor  too  high.  If  the  former,  the  meiler  is 
extinguished,  and  the  kindling  anew  is  difficult  on  account 
of  the  steam  already  developed  in  the  centre  of  the  chim- 
ney and  attaching  to  the  billets  in  the  form  of  water,  and 
threatening  to  choke  or  extinguish  the  fire  put  down.  If 


HAND-BOOK   FOR    CHARCOAL    BURNERS.  53 

the  heat  be  too  great  the  coaling  progresses  too  fast  in  the 
beginning  and  becomes  difficult  to  manage.  Green  wood 
of  course  requires  a  higher  kindling  heat  than  dry  wood. 

In  covering  the  chimney  the  tilling  should  reach  over 
the  top,  so  that  we  may  observe  when  it  settles.  The  vent 
is  covered  with  a  large  turf,  the  grass  side  being  turned 
down.  Around  it  is  put  spruce  brushwood  and  then  all 
is  covered  with  charcoal  dust,  but  this  dust  should  in  the 
beginning  be  so  loose  that  the  steam  and  smoke  may 
somewhat  easily  get  through  and  permit  sufficient  draught 
through  the  chimney.  When  the  charcoal  covering  on 
the  thatching  is  of  a  rather  thin  or  loose  quality,  the 
gases  in  the  meiler  more  easily  escape  through  the  cover- 
ing. In  place  of  turf  many  colliers  use  pieces  of  green 
split  pine  blocks,  which  are  laid  with  the  flat  side  down  ; 
these  are  not,  however,  as  serviceable,  for  they  are  not  as 
pliable  as  turf,  and  hence  they  do  not  indicate  so  well 
when  the  filling  in  the  chimney  settles. 

After  two  or  three  hours  the  kindling  vent  is  reopened 
to  see  whether  the  fire  continues  to  burn  and  to  fill  up 
with  charcoal  or  wood,  in  place  of  that  which  has  been 
consumed  in  the  chimney.  The  fire  is  now  generally,  es- 
pecially if  the  meiler  has  been  built  of  green  wood,  quite 
low,  and  in  that  case,  in  order  that  the  fire  may  be  in- 
creased, it  is  well  to  leave  the  chimney  uncovered  a  short 
time,  before  the  charcoal  dust,  the  latter  loosely  packed, 
is  put  on  again.  When  the  settling  of  the  turf  again  in- 
dicates that  the  fuel  in  the  chimney  has  been  consumed 
to  a  considerable  extent,  it  should  be  replaced  by  new  well 


54  HAND-BOOK   FOR   CHARCOAL    BURNERS. 

packed  fuel.  This  operation  is  repeated  time  and  again 
in  the  manner  described,  with  this  precaution,  that  if  there 
is  no  danger  of  the  fire  going  out,  the  vent  of  the  chimney 
is  kept  open  each  time  as  short  a  while  as  possible.,  To  se- 
cure this  the  fuel  should  be  brought  on  to  the  covering  be- 
forehand, so  that  it  may  be  close  at  hand  when  it  is  used  ; 
the  canals  should  be  closed  during  filling.  The  filling-rod 
should  be  used  freely  to  scrape  down  from  the  sides  of  the 
chimney,  to  pack  and  work  together  the  already  charred  or 
partly  consumed  fuel  in  the  chimney,  before  putting  in 
any  new.  During  this  operation  it  is  necessary  to  be  care- 
ful, so  as  not  to  permit  any  charcoal  dust  falling  down. 
Whenever  the  fire  is  apt  to  get  too  hot,  the  meiler  should 
remain  closed  a  while  after  each  filling,  before  the  canals 
are  opened  ;  and  likewise  the  charcoal  covering  should  be 
gradually  packed  more  and  more  as  the  chimney  gets 
more  heated  ;  still  this  should  be  done  with  considerable 
care,  so  that  the  steam  may  somewhat  easily  escape,  which 
is  a  very  important  matter  and  is  facilitated  by  occasion- 
ally raking  and  turning  the  dust  on  the  covering. 

As  has  been  stated  the  settling  of  the  chimney  cap 
shows  when  new  filling  is  needed.  But  it  may  happen 
that  the  fuel  sticks  fast  in  the  chimney  and  may  be  to  a 
great  extent  consumed  without  any  settling  being  percepti- 
ble, and  hence  an  examination  with  the  rod  is  occasionally 
required. 

During  the  first  24  hours  3  to  4  fillings  are  usually  re- 
quired, during  the  second  and  third  about  2,  and  a  few 
days  after  that,  only  1.  As  a  rule  we  may  say  that  the 


HAND-BOOK   FOR   CHARCOAL    BURNERS.  55 

stronger  the  draught  is,  as  for  instance  in  windy  and 
stormy  weather,  the  oftener  it  is  necessary  to  fill  the  chim- 
ney. After  24  hours  or  a  little  less  we  may  assume  that 
the  meiler  is  properly  kindled,  and  we  will  now  ex- 
amine more  carefully  what  changes  take  place  in  its 
interior. 

At  the  moment  when  the  fire  is  kindled,  all  the  vacant 
spaces  from  the  bottom  to  the  top  are  filled  with  atmo- 
spheric air.  It  is  this  air  that  sustains  the  first  combustion 
in  the  lower  part  of  the  chimney,  while  the  gaseous  pro- 
ducts of  combustion  rapidly  make  their  escape  through 
the  upper  part  of  the  chimney,  which  is  still  open  and 
serves  the  same  purpose  as  a  common  stove-pipe.  While 
these  gaseous  products  pass  through  the  not  yet  heated 
fuel  in  the  upper  part  of  the  chimney  they  gradually  heat 
and  dry  it,  while  they  also  protect  it  more  or  less  perfectly 
from  coming  in  contact  writh  the  atmospheric  air,  which  is 
found  in  the  upper  parts  of  the  meiler.  This  fuel  and  the 
wood  immediately  surrounding  the  chimney  is  now  sub- 
ject to  a  kind  of  coaling  process.  This  process  as  well  as 
the  combustion  near  the  hearth  would  soon  cease,  if  new 
atmospheric  air  did  not  stream  in  through  the  opened 
canals  and  replace  the  air,  whose  oxygen  has  been  con- 
sumed in  sustaining  the  fire.  The  greater  or  less  vigor  of 
the  fire  depends  especially  upon  the  strength  of  the 
draught,  upon  the  greater  or  less  number  and  size  of  the 
canals ;  its  vigor  is  increased  very  much  also  by  the  com- 
bustion and  draught  having  the  same  outlet,  which  in 
kindling  the  meiler  (an  operation  which  is  to  be  made  as 


56  HAND-BOOK    FOE   CHARCOAL    BURNERS. 

easy  and  convenient  as  possible)  does  no  injury,  but  on 
the  contrary  is  of  great  advantage. 

By  afterwards  putting  a  cap  on  the  chimney  filled  with 
well  packed  fuel  a  great  diminution  of  draught  is  pro- 
duced, which  now  has  to  find  its  way  through  the  char- 
coal dust,  partly  around  the  turf  cap  of  the  chimney,  and 
partly  through  the  covering  itself.  The  result  of  this  is 
that  the  products  of  combustion  do  not  remain  any  longer 
exclusively  in  the  chimney,  but  get  into  all  openings  be- 
tween the  billets,  and  partly  mix  with  the  atmospheric  air 
found  there,  and  partly  press  this  air  out  before  them 
through  the  charcoal  dust  covering.  This  is  especially 
true  of  nitrogen,  carbonic  oxide,  etc.,  products  of  com- 
bustion, that  do  not  assume  a  liquid  form  at  a  low  tem- 
perature ;  while  other  substances  such  as  watery  steam,  tar- 
steam,  etc.,  when  mixed  with  the  cold  air  and  come  in  con- 
tact wTith  the  cold  wood  near  the  periphery  of  the  meiler, 
condense  in  the  form  of  water,  tar,  etc.,  which  run  along 
the  wood  to  the  hearth.  In  the  same  degree  as  the  char- 
coal dust  covering  permits  air,  watery  steam,  and  other 
substances  to  escape,  new  air  is  drawn  in  through  the. ca- 
nals, and  this  air  continues  to  be  drawn  especially  to  the 
bottom  of  the  chimney,  partly  because  the  outgoing 
draught  is  strongest  at  this  point  where  the  fire  is  situated, 
and  partly  because  in  the  very  making  of  the  m&Uer,  its 
lower  part  is  the  most  open,  and  therefore  gives  the  least 
resistance  to  the  pouring  in  of  the  air.  After  the  fire  and 
draught  have  begun  to  operate  freely,  the  air  enters  both 
through  the  charcoal  dust  on  the  sides  of  the  meiler  and 


HAND-BOOK    FOR    CHAKCOAL    BUHNERS.  57 

through  the  hearth,  when  this  is  not  perfectly  tight ;  and 
in  this  way  we  explain  that  the  fire  in  the  chimney  may 
be  sustained  for  some  time,  evren  when  the  canals  are  closed, 
and  also  that  the  draught  is  stronger  in  windy  weather. 
Each  of  the  several  times,  when  the  cap  of  the  chimney  is 
taken  off  for  tilling  in  new  fuel,  the  products  of  combus- 
tion are  drawn  more  and  more  to  the  chimney,  where  they 
can  escape  unhindered,  and  when  it  is  put  on  they  spread 
again,  especially  in  the  upper  parts  of  the  meiler.  Some- 
times the  fireplace  in  the  bottom  of  the  chimney  is 
widened  so  that  the  wrood  around  the  lower  part  of  the 
chimney  is  first  dried,  then  coaled,  and  finally  consumed. 
Above  the  fireplace  drying  and  coaling  progress  as  well  of 
the  fuel  as  of  the  metier-wood  lying  immediately  around  it. 

The  Three  Principal  Periods  of  Coaling. 

Although,  in  the  nature  of  the  case,  the  changes  which 
now  take  place  in  the  meiler  from  the  time  it  is  kindled 
until  the  whole  coaling  process  is  closed,  are  not  distinctly 
separated  from  each  other,  we  may  still  distinguish  in  the 
coarse  of  coaling  three  chief  periods,  of  which  the  first  is 
characterized  among  other  things  by  the  fact  that  the 
coaling  process  goes  on  only  in  the  centre  of  the  meiler 
in  and  around  the  chimney  and  moves  almost  cylindrically 
upwards,  while  in  the  second  period  the  coaling  takes 
more  and  more  direct  course  to  the  sides  of  the  meiler, 
until  the  upper  part  of  the  meiler  is  coaled,  and  during  the 
third  or  last  period  the  coaling  proceeds  from  the  already 

formed  charcoal  and  round  about  the  charred  centre  of 
3* 


58  HAND-BOOK    FOR    CHARCOAL    BURNERS. 

the  metier  like  a  cloak  downwards  and  outwards  to  the 
foot  of  the  meiler. 

THE   FIRST  PERIOD    OF    COALING. 

Heat  at  Foot  of  Meiler. 

The  first  period  is  more  a  drying  than  a  coaling  period. 

It  has  already  been  mentioned  how  the  filling- wood 
put  down  into  the  chimney,  as  well  as  the  billets  nearest 
the  chimney,  by  drying  produces  a  large  quantity  of 
steam,  the  most  of  which,  the  meiler-wood  being  cold,  is 
condensed  and  runs  to  the  hearth  in  form  of  water.  Im- 
mediately back  of  the  dry  wood  nearest  the  chimney  there 
is  then  found  a  portion  of  damp  wood,  and  near  the  hearth 
the  wood  may  be  perfectly  saturated  with  water.  If  we 
now  reflect  that  the  fire,  even  though  the  wood  be  quite 
dry,  burns  slowly  in  the  direction  opposite  the  draught, 
then  it  is  easy  to  understand  why  there  is  not  much 
danger  of  the  fire  going  out  too  soon  at  the  lower  part  of 
chimney  in  the  beginning  of  the  coaling.  On  the  con- 
trary, it  is  the  first  business  of  the  collier  to  remove  what- 
ever hinders  the  preservation  of  heat  at  the  bottom  of  the 
chimney,  and  to  produce  a  gradual  and  uniform  drying 
and  coaling  of  the  wood  on  all  sides  of  the  meiler.  For 

O 

if  we  do  not  now  succeed  in  making  the  meiler  warm  at 
the  foot,  it  never  will  be  warm  there,  and  hence  after  the 
coaling  operation  there  will  be  near  the  hearth  a  quantity 
of  brands  and  half -charred  wood.  In  the  winter  season  it 
may  also  happen,  if  the  lower  part  of  the  in.eiler  is  not 


HAND  -BOOK    FOR    CHARCOAL    BURNERS.  59 

properly  heated,  that  the  water,  from  condensation,  in 
running  down  freezes  to  ice,  whereby  the  billets  become 
so  fastened  to  each  other  and  to  the  frozen  hearth  that 
they  cannot  settle  in  the  course  of  coaling ;  and  settling  is 
absolutely  necessary,  if  the  coaling  is  to  be  successful,  as 
will  be  shown  below. 

We  now  find  how  profitable  it  must  be  to  have  the 
billets  nearest  the  chimney  perfectly  dry,  and  that  brands 
are  still  better  than  the  driest  wood.  "We  likewise  see 
how  injurious  a  sour  hearth  saturated  with  water  must  be  ; 
on  the  other  hand  we  must  notice  the  importance  of  hav- 
ing the  hearth  somewhat  convex,  so  that  the  water  may 
run  off  rapidly  on  all  sides.  Very  much  depends  upon 
the  experience,  thoughtfulness,  and  care  of  the  collier. 
The  greener  the  wood  and  sourer  the  hearth,  the  more 
necessary  it  is  that  the  chimney  should  be  constantly  well 
filled  with  dry  fuel ;  that  the  canals  should  be  sufficient 
in  number  and  size ;  that  the  covering  of  charcoal  dust 
should  be  well  packed  down,  and  that  the  chimney  at  each 
filling  be  kept  open  as  short  a  time  as  possible. 

We  may,  however,  go  too  far  in  applying  these  rules,  for 
if  the  charcoal  dust  be  kept  too  tight  the  first  twenty-four 
hours  and  the  canals  be  too  large,  more  or  less  violent  ex- 
plosions may  easily  take  place  in  the  meiler,  of  which 
more  hereafter. 

Changes  in   Upper  Part  of  Meiler. 

While,  then,  if  the  mciler  has  been  properly  made  and 
the  collier  understands  his  business,  the  fire  gradually 


60         HAND-BOOK  FOR  CHARCOAL  BURNERS. 

spreads  uniformly  on  all  sides  from  the  bottom  of  the 
chimney,  whereby  it  cannot  be  avoided  that  a  part  of  the 
charcoal  produced  by  the  billets  is  burned  to  ashes,  the 
upper  part  of  the  meiler  undergoes  a  much  greater 
change.  In  the  chimney  itself  the  draught  is  upwards ; 
thus  it  has  the  same  direction  as  the  combustion  of  the 
kindling-wood,  and  hence  the  combustion  is  more  vigor- 
ous, especially  as  the  fire  on  its  way  upward  always  finds 
perfectly  dry  fuel.  The  degree  of  heat  in  the  centre  and 
upper  part  of  the  chimney,  where  the  gaseous  products  of 
combustion  coming  up  from  below  still  contain  a  greater 
or  less  quantity  of  unconsumed  atmospheric  air  (not  con- 
sidering the  air,  which  finds  its  way  thither  more  or  less 
directly  both  from  the  canals  and  through  the  porous 
mantle  of  charcoal  dust  on  the  sides  of  the  metier),  natu- 
rally grows  high  in  a  very  short  time.  The  drying  as 
well  as  the  coaling  of  the  surrounding  billets  is  here  done 
quite  rapidly  and  unhindered,  wherefore  also,  in  these 
parts  of  the  meiler,  the  coaling  takes  a  wider  range  than 
near  the  hearth.  The  charcoal  produced  is,  however,  on 
account  of  the  main  direction  of  the  draught  being 
through  the  already  coaled  to  the  uncoaled  material,  much 
exposed  to  further  combustion. 

What  the  collier  here  has  to  do  is  at  each  filling  to  push 
down  \vith  the  filling-rod  round  about  the  meiler  all  the 
charcoal  and  wood  lying  loose  therein,  packing  them  well 
in  the  bottom  of  the  chimney  and  then  fill  well  again  with 
new  fuel,  which  must  be  packed  as  hard  and. tight  as  pos- 
sible. If  this  is  neglected,  it  easily  happens  that  the  fire 


HAND-BOOK  FOR   CHARCOAL    BURNERS.  61 

makes  its  way  too  rapidly  from  the  chimney  to  some  of 
the  sides,  by  which  the  coaling  operation  is  very  much  in- 
jured and  may  become  wholly  unmanageable. 

Sweating  of  Meiler. 

The  deposit  of  steam  containing  water  and  tar,  etc.,  on 
the  billets  begins  of  course  immediately  after  the  meiler 
is  kindled,  but  this  dampness  is  not  of  much  importance 
before  the  second  or  third  day,  when  the  meiler  has 
become  sufficiently  heated  in  and  around  the  chimney. 
We  now  say  that  the  meiler  sweats.  This  sweating  also 
shows  itself  on  the  charcoal  dust  covering,  which  already, 
during  the  first  twenty-four  hours,  begins  to  become  damp, 
which  dampness  gradually  increases  during  the  next  few 
days,  then  it  decreases  and  finally  entirely  disappears. 
The  time  of  its  disappearance  varies  with  the  size  and 
care  of  the  meiler  and  the  dryness  of  the  billets.  It  may 
take  place  on  the  fourth  or  fifth  day  after  kindling,  or  not 
before  a  week  or  more. 

When  the  sweating  of  the  covering  ceases,  this  is  a  sign 
that  the  covering  wood  has  for  the  most  part  become  so 
thoroughly  heated  and  dried  that  its  coaling  has  already 
begun,  and  that  the  second  period  of  the  care  of  the  rmeiler 
is  entered  upon. 

Advantage  of  Heating  Meiler  Slowly. 

It  is  evident  that  the  drier  the  billets  are,  the  larger  the 
canals,  and  the  thinner  and  looser  the  covering,  the  sooner 
the  covering  wood  will  reach  so  high  a  temperature  (180° 


62  HAND- BOOK   FOR   CHARCOAL    BURNERS. 

Fahr.)  that  the  steam  rising  is  not  to  any  great  extent 
condensed  thereon.  But  there  is  at  least  one  important 
reason  for  not  heating  the  meiler  too  rapidly  in  the  begin- 
ning, and  this  is,  that  the  lower  the  average  temperature 
during  the  coaling  process,  the  more  charcoal  we  get, 
according  to  experiments  explained  heretofore,  and  on  the 
contrary,  the  more  the  coaling  process  is  hastened  by  in- 
creased draught  and  heat  in  the  meiler  the  more  charcoal 
is  lost  in  the  form  of  several  gaseous  substances.  Just 
here  much  depends  upon  the  judgment  and  experience  of 
the  collier  in  seeing  that  the  charring  is  not  pushed  too 
fast.  It  rarely  happens  that  a  meiler  is  coaled  too  slowly. 
And  yet  this  disadvantage,  consisting  almost  exclusively  in 
loss  of  time,  is  far  less  important  than  the  opposite  and 
more  common  error  (which  is  rather  the  rule  than  an 
exception),  namely,  that  the  coaling  is  hurried  on  too 
rapidly.  This  may  take  place  only  periodically,  when  the 
filling  of  the  chimney  is  done  too  slowly  without  closing 
the  canals  in  the  meantime.  But  in  regard  to  this  we  can 
add  nothing  to  what  has  already  been  said. 

N".  B. — It  may  happen,  if  the  meiler  is  coaled  too  slowly, 
with  a  too  low  temperature,  that  we  do  not  get  black 
ringing  charcoal,  but  a  brand-like  charcoal  of  a  brownish 
color. 

Smoke  of  Meiler. 

However  important  it  may  be  in  general  to  observe  the 
character  of  the  smoke  coming  through  the  dust,  still  this 
is  especially  important  in  judging  of  the  farther  advance- 


HAND-BOOK    FOR    CHARCOAL    BURNERS.  63 

ment  of  the  coaling  process.  At  present,  it  must  suffice 
to  say  that,  during  the  first  days  of  coaling,  the  smoke, 
which  then  contains  a  large  quantity  of  steam,  is  thick, 
heavy,  and  moves  upward  in  puffs,  while  its  color  is  a 
dirty,  whitish  gray,  verging  more  or  less  on  yellow ;  after 
which,  just  as  the  billets  dry,  and  the  water  contained  in 
the  escaping  gases  is  consequently  diminished,  the  smoke 
gradually  grows  more  transparent,  thinner,  lighter,  and 
whirls  up  with  great  rapidity.  In  the  beginning,  nearly 
as  long  as  only  water  escapes  from  the  wood,  the  smoke 
is  almost  entirely  free  from  smell ;  but,  as  the  coaling  of 
the  wood  grows  more  lively  and  extensive,  the  well-known 
peculiar  smell,  by  which  a  coaling  meiler  is  detected  at  a 
great  distance,  becomes  more  distinct. 

Explosions  in  Jlfeiler. 

Of  the  things  that  may  cause  serious  interference  with 
the  even  advancement  of  the  coaling  process,  we  must, 
first  of  all,  mention  explosions  in  the  meiler.  It  fre- 
quently happens,  especially  during  the  day,  when  the 
meiler  sweats  most  freely,  that  suddenly,  time  after  time, 
not  only  the  dust  in  different  parts  of  the  covering  is 
thrown  off,  but  also  the  brushwood  underneath  is  here 
and  there  turned  completely  over.  Sometimes  it  even 
happens  that  single  pieces  of  wood  are  thrown  out,  while 
at  the  same  time  a  greater  or  less  portion  of  the  meiler 
is  violently  shaken.  We  then  say  that  the  meiler  ex- 
plodes. Just  in  proportion  as  this  phenomenon  is  fami- 
liar to  all  who  have  had  anything  to  do  with  coaling,  so 


64  HAND-BOOK   FOR   CHARCOAL   BURNERS. 

are  the  ideas  usually  entertained  of  its  true  cause  vague 
and  uncertain.  The  true  cause  is  that  the  steam  con- 
stantly developed  from  the  wood  when  drying,  if  it  can- 
not escape  easily  through  the  too  thick  or  too  compact 
dust  covering,  becomes,  about  like  the  steam  in  a  well- 
heated,  closed  boiler,  so  compressed,  that  it  finally  vio- 
lently makes  its  way  through  the  dust  in  the  same  manner 
as  the  steam,  when  the  pressure  becomes  sufficiently 
strong,  bursts  the  boiler.  But  this  explanation  is  not  en- 
tirely satisfactory.  For  we  know,  that  during  these  very 
days,  when  the  meiler  sweats  the  most,  steam  is  condensed 
in  great  quantities  in  the  parts  of  the  meiler  that  are  yet 
cold ;  and  it  must  be  borne  in  mind  that  if  the  steam 
pressure  in  the  meiler  should  gradually  increase  to  the  ex- 
tent of  becoming  perceptibly  greater  than  the  atmo- 
spheric pressure,  then  no  more  air  could  enter  through 
the  canals  and  dust  covering ;  but  on  the  contrary,  the 
steam  and  gases  would  escape  through  these  very  same 
canals,  until  the  pressure  in  the  meiler  becomes  even  with 
the  pressure  of  air  from  the  outside.  Furthermore,  it  is 
scarcely  supposable,  that  so  great  a  quantity  of  steam 
could  possibly  be  developed  as  it  were  in  a  moment,  that  it 
could  be  able  to  produce  an  explosion,  in  spite  as  it  were 
of  the  canals,  the  more  or  less  porous  quality  of  the  dust, 
and  the  yet  cold  condition  of  the  meiler..  Yet  this  does 
not,  in  its  results,  differ  from  explosions  of  steam  boilers. 
But  we  know  with  certainty  that  in  the  meiler  there 
are  constantly  developed  all  kinds  of  gaseous  substances, 
carbonic  oxide,  carburetted  hydrogen,  etc.,  which  if  mixed 


HAND-BOOK   FOR    CHARCOAL   BURNERS.  65 

with  atmospheric  air  and  coming  in  contact  with  the 
smallest  spark  of  fire,  immediately  explode.  It  is  indeed 
true  that  these  gases  mentioned  gradually  make  their 
way  through  the  dust  covering,  but  it  does  not  follow  that 
this  is  done  uniformly  everywhere,  but,  on  the  contrary, 
there  is  every  probability,  especially  during  the  first 
period  of  coaling,  before  the  meiler  has  got  any  smoke 
vents  (of  which  more  below),  that  here  and  there  in  the 
meiler,  especially  in  its  upper  parts,  are  formed  greater 
or  less  gathering  of  gases  that  for  a  time  remain  quiet. 
These  cannot  well  escape  mixing  with  the  atmospheric 
air,  which  enters  through  the  canals,  the  chimney  in  being 
filled,  and  wherever  it  can  through  the  more  or  less  tight 
sides  of  the  meiler.  The  more  we  consider  the  matter,  the 
more  we  must  be  convinced  that  such  a  more  or  less  com- 
plete mixing  of  the  combustible  gases  with  the  atmo- 
spheric air,  or  the  formation  of  explosive  gas  must  take 
place  in  different  parts  of  the  meiler;  and  this  too,  not 
only  during  the  time  of  sweating,  but  also,  though  it  be  in 
a  less  degree,  both  before  and  after  this  time.  But  in 
order  that  this  explanation  may  be  accepted,  we  must 
see  whether  it  corresponds  with,  experience.  This  ex- 
perience is  the  following :  This  explosion  may  occur  to 
a  certain  extent  by  keeping  the  dust  during  the  first  days 
of  coaling  loose,  and  admitting  as  little  air  as  the  circum- 
stances will  permit.  A  meiler  made  from  green  billets 
has  a  greater  tendency  to  explode  than  a  meiler  made 
from  dry  wood  ;  a  sour  hearth  than  a  dry  one.  The  ex- 
plosion may  take  place  while  the  collier  is  busy  packing 


66  HAND-BOOK    FOR  CHARCOAL    BURNERS. 

down  such  places  in  the  covering  as  have  become  loose, 
or  is  doing. some  work  in  the  covering,  by  which  the 
draught  in  some  part  is  either  increased  or  diminished. 
The  explosion  is  often  indicated  beforehand  by  the  devel- 
opment of  smoke  suddenly,  almost  ceasing ;  finally  this 
explosion  takes  place  almost  exclusively  during  the  first 
days,  while  the  meiler  sweats. 

In  the  first  place,  in  regard  to  the  dust  covering,  it  is 
evident  that  the  thinner  it  is  kept,  and  the  more  fre- 
quently it  is  raked  into  and  stirred  up,  the  more  freely 
the  steam  and  gas  developed  in  the  meiler  can  make  their 
way  through  it.  There  will  therefore  be  a  greater  motion 
and  change  of  the  gaseous  substances  everywhere  in  the 
meiler,  and  this  will  counteract  the  formation  of  large 
gatherings  of  explosive  gases.  But  a  thin  and  loose  dust 
covering  makes  an  easier  escape,  not  only  for  the  combus- 
tible gases,  but  also,  of  course,  for  the  steam.  Hence  the 
thinner  and  looser  the  dust  covering,  the  less  the  meiler 
sweats,  just  as  a  meiler  of  dry  billets  on  dry  ground 
must,  other  things  being  equal,  sweat  less  than  a  meiler 
of  green  billets  on  a  sour  hearth  ;  and  finally  a  meiler 
heated  slowly  by  a  moderate  admittance  of  air  sweats 
slower  and  less  violently  than  a  meiler  in  which  the  heat- 
ing process  is  hurried  on  too  rapidly  already  from  the 
beginning,  by  a  free  admittance  of  air.  But  the  more  the 
m,eiler  sweats,  the  more  the  dust  becomes  soaked,  heavy, 
sticky,  and  impenetrable.  A  violent  sweating,  therefore, 
operates  about  in  the  same  manner  as  a  thick,  well  packed 
dust  covering. 


HAND-BOOK    FOR   CHARCOAL    BURNERS.  67 

In  order  that  the  explosive  gas  formed  may  explode,  it 
must  come  in  contact  with  tire.  But  a  single  spark  from 
a  crackling  piece  of  wood  is  all  that  is  needed  to  produce 
the  explosion.  It  may,  however,  usually  be  the  case  that 
the  explosive  gas  is  drawn  toward  some  place  where  there 
is  fire.  Such  a  drawing  or  suction  may  be  caused  by  a 
change  in  the  strength  or  direction  of  the  draught  in  the 
meUer.  Supposing  the  dust  on  one-half  of  the  covering 
is  tightened  or  packed,  then  the  gaseous  substances,  which 
formerly  had  a  free  escape  here,  must  be  drawn  to  the  op- 
posite side  of  the  meiler,  where  the  escape  is  more  easy, 
and  thus  we  can  explain  that  the  explosion  often  seems 
to  be  caused  by  some  work  done  to  the  covering.  The 
same  thing  applies  to  the  observation  that  the  explosion 
is  frequently  indicated  beforehand  by  a  sudden  diminu- 
tion of  the  smoke.  The  decrease  of  smoke  shows  either 
that  the  development  of  gas  from  the  drying  and  coaling 
wood  for  some  reason  suddenly  diminishes,  or  that  the 
condensing  of  steam  suddenly  increases;  hence  that 
some  change  has  taken  place  in  the  meiler,  which  often 
may  produce  such  a  change  in  the  direction  of  the 
draught,  that  some  explosive  gas  formerly  protected  from 
the  lire,  now  comes  in  contact  with  it. 

Finally,  that  the  explosion  almost  always  takes  place 
during  the  time  of  sweating  is  no  proof  that  explosive  gas 
is  not  formed,  and  that  explosions  do  not  take  .place  before 
and  after  this  time.  On  the  contrary,  it  is  quite  probable 
that  smaller  explosions  or  puffs,  although  so  feeble  that 
they  are  not  noticed,  take  place  in  a  far-advanced  stage  of 


68  HAND-BOOK   FOR   CHARCOAL    BURNERS. 

the  coaling,  and  we  also  have  examples  of  explosions  actual- 
ly taking  place  both  before  and  after  the  sweating  time. 

In  order  to  prevent  explosions  as  much  as  possible,  the 
collier  should  keep  the  dust  loose  on  the  covering  by  fre- 
quently raking  and  turning  it,  and  admit  as  little  air  as  the 
circumstances  will  permit ;  and  the  greener  the  billets  and 
the  sourer  the  hearth,  of  the  greater  importance  it  is  to  ob- 
serve these  rules  carefully.  They  do  not  agree  well  with 
rules  given  above  for  securing  the  proper  heat  of  the  foot 
of  the  meiler,  and  hence  the  discernment  and  judgment  of 
the  collier  are  here  particularly  called  for. 

When  the  smoke  suddenly  diminishes,  and  the  collier 
may  therefore  look  for  an  explosion,  all  the  canals  should 
be  closed  quickly,  and  after  the  explosion  the  meiler  should 
without  delay  be  carefully  covered  again  every  time  it 
explodes. 

If  this  is  not  done,  and  the  meiler  is  permitted  to  stand 
uncovered  for  some  time,  the  heat  rises  too  high,  from 
which  loss  of  charcoal  always  results.  Many  a  meiler  has 
burned  up  completely,  because  there  was  not  a  sufficient 
number  of  workmen  to  cover  it  quickly  enough  after  the 
explosion. 

Since  these  explosions  always  produce  an  increased  heat, 
this  should  be  decreased  again  as  far  as  possible  after  the 
meiler  has  ceased  to  explode,  which  is  done  by  keeping  the 
dust  tight  and  by  letting  the  cooling  be  done  blind,  that 
is  to  say,  with  the  canals  closed  about  24  hours. 

Finally,  it  should  be  mentioned  that  a  moderate  explosion 
is  in  some  respects  beneficial,  for  it  makes  the  meiler  tight- 


HAND-BOOK   FOR    CHARCOAL   BURNERS.  69 

er  and  less  steep,  and  we  have  many  instances  that  even 
meilers  that  have  exploded  quite  violently,  have  after- 
wards become  quiet  and  produced  much  and  good  char- 
coal. 

Shrinkage  of  Billets. 

The  coaling  process  may  also  become  disordered  by  the^ 
quality  of  the  wood,  already  mentioned,  that  it  shrinks 
more  the  drier  it  gets.  This  shrinking  of  course  continues 
without  interruption  during  the  whole  coaling  process,  but 
while  it  goes  on  quietly  and  constantly  it  ought  not,  if  pro- 
per attention  is  given  on  the  part  of  the  collier,  to  do  any 
harm.  It  produces  cracks  and  openings  in  the  covering, 
which  may  be  remedied  by  packing  down  firmer  the  wood 
and  dust,  and  possibly  even  by  putting  down  some  fine 
wood  here  and  there. 

Progress  of  fire  from  Chimney. 

Far  more  dangerous  is  the  disorder  referred  to  above, 
which  may  arise  by  the  fire  for  some  reason  or  other  (for 
instance,  when  the  billets  are  not  raised  properly,  improper 
draught,  windy  wreather,  etc.)  making  its  way  too  soon  from 
the  chimney,  and  it  has  already  been  stated  what  the  col- 
lier has  to  do  to  prevent  such  a  spreading  of  the  fire. 

If,  however,  this  has  already  taken  place,  large  vacant 
places  may  be  formed,  before  the  billets  and  charcoal  above 
are  able  to  settle  in.  Hence  the  collier  should  examine  in 
season  whether  such  vacant  spaces  have  been  formed.  If 
they  are  not  too  far  below  the  covering  they  may  be  dis- 
covered by  the  hollow  sound  produced  by  striking  the 


70  HAND-BOOK    FOR    CHARCOAL    BURNERS. 

covering  with  a  mallet  or  club.  The  dust  and  brushwood 
should  then  be  taken  away,  the  thatching  should  be  thrust 
down,  and  the  vacant  space  thus  becoming  accessible  should 
be  filled  with  wood,  brands,  or  charcoal  carefully  packed 
down,  and  then  new  covering  should  be  put  on.  When  in 
spite  of  the  filling  the  fire  spreads  too  rapidly,  other  rem- 
edies must  be  resorted  to,  the  description  of  which  properly 
belongs  below,  since  the  consumption  of  charcoal,  leaving 
hollow  places  in  the  meiler,  occurs  chiefly  during  the  second 
period  of  coaling. 

In  stormy  weather,  if  screens  are  not  put  up,  the  air  pen- 
etrates far  more  easily  than  otherwise  through  the  dust 
covering  of  that  side  of  the  meiler  which  is  towards  the. 
wind.  Thereby  the  fire  gets  a  tendency  to  move  from 
the  chimney  on  the  windward  side,  for  which  reason  the 
canals  on  the  opposite  side  should  be  limited  in  num- 
ber and  size  of  openings  according  to  the  strength  of  the 
wind,  the  unprotected  situation  of  the  meil&r,  etc.  If  the 
wind  is  very  severe  it  may  be  necessary  to  close  the  canals 
entirely,  and  besides  put  on  more  dust  and  pack  it  careful- 
ly. The  screens  mentioned  above  may  be  made  from 
splinters  fastened  to  a  wooden  frame  and  braided  with 
brushwood,  straw,  etc. 

As  a  general  rule,  we  may  say  that  if  the  fire  for  some 
reason  or  other  is  drawn  from  the  chimney  to  one  of  the 
sides,  this  can,  if  noticed  in  time,  to  a  certain  extent  be  reme- 
died by  diminishing  or  closing  the  openings  of  the  canals 
and  tightening  the  dust  covering  on  the  same  side, 
or  by  increasing  or  making  larger  the  openings  of  the 


HAND-BOOK   FOR   CHARCOAL    BURNERS.  71 

canals  opposite  so  as  to  facilitate  the  admittance  of  air  on 
this  side  for  the  purpose  of  drawing  the  fire  back  to  the 
centre  of  the  chimney.  There  will,  however,  always  be 
more  or  less  loss  of  charcoal. 


THE    SECOND    PERIOD    OF    COALING. 

The  second  period,  during  which,  according  to  what  has 
already  been  said,  the  coaling  progresses  in  a  more  hori- 
zontal direction  from  the  chimney,  may  be  assumed  to  be- 
gin about  the  time  when  the  sweating  of  the  covering  has 
ceased.  The  billets  have  then  become  perfectly  dry,  and 
have  everywhere  reached  at  least  the  temperature  at  which 
the  solid  texture  of  the  wood  begins  to  yield,  or  in  other 
words  the  wood  begins  to  coal.  It  is,  however,  quite  prob- 
able that  before  the  dust  has  become  perfectly  dry,  the 
covering  wood  nearest  the  chimney  has  already  become 
more  or  less  perfectly  coaled.  In  the  whole  process  of 
coaling  no  definite  dividing  lines  can  be  drawn. 

Condition  of  Meiler  at  Beginning  of  Second  Coaling 

Period. 

The  coaling  b  eing  begun  properly,  the  meiler  will  now 
contain  the  following  solid  parts :  1.  A  cylindrically  or 
rather  conically  shaped  layer  of  principally  glowing  char- 
coal, which  near  the  hearth,  if  the  meiler  has  been  man- 
aged so  as  to  heat  it  properly  at  the  foot,  extends  2  to  3 
feet  from  the  chimney  into  the  surrounding  billets.  2. 
Perfectly  dry  and  partly  charred  wood,  as  well  through  the 


72  HAND-BOOK   FOR   CHARCOAL    BURNERS. 

covering,  where  the  wood  has  not  been  coaled,  as  around 
the  coaled  centre  of  the  meiler.  3.  A  belt  of  more  or  less 
imperfectly  dried  billets.  4.  An  outside  layer  of  billets, 
that  are  still  quite  green  and  sour.  This  layer  is  thinnest 
near  the  brow,  where  it  begins,  and  thickest  at  the  foot, 
where  the  most  air  enters  and  cools  the  wood,  and  where 
most  of  the  water  from  the  condensed  steam  is  gathered. 

The  volatile  substances  found  in  the  meiler  are  chiefly 
the  same  as  have  been  mentioned  before,  but  with  this 
important  difference,  that  watery  steam  now  exists  in  a 
far  less  quantity  than  daring  the  first  days  after  igniting 
the  meiler.  We  must  also  observe  that  the  steam  and 
gases  in  the  covering  and  immediately  beneath  it  now 
gradually  assume  a  higher  temperature,  which  certainly  is 
not  less  than  216°  Fahr.,  but  may  rise  considerably  above 
this ;  while,  on  the  other  hand,  near  the  foot  of  the  meiler  ^ 
where  a  stream  of  cold  air  constantly  pours  in  from  all 
sides,  the  temperature  may  not  be  much  higher  than  that 
of  the  atmospheric  air. 

Smoke-  Vents. 

During  the  first  period  of  coaling  it  cannot  be  avoided 
that  in  and  near  the  chimney  quite  an  amount  of  char- 
coal is  lost,  remaining  partly  in  the  form  of  ashes,  and 
partly  in  the  form  of  weak,  loose,  half-consumed  charcoal. 
The  best  proof  of  this  is  the  severe  task  of  tilling,  which 
recurs  time  and  again,  and  for  which  300  to  800  cubic 
feet  of  wood  is  consumed  ;  and  the  reason  of  this  is,  ac 
cording  to  what  has  been  shown,  that  the  draught  is  for 


HAND-BOOK   FOR   CHARCOAL   BURNERS.  73 

the  most  part  in  the  same  direction  as  the  coaling  process. 
This  is  undoubtedly  a  great  disadvantage  in  this  method 
of  coaling,  but  when  the  coaling,  and  if  you  please,  the 
combustion  has  reached  the  upper  part  of  the  chimney, 
this  disadvantage  grows  less  perceptible,  and  when  the 
work  is  well  done,  may,  at  the  beginning  of  the  second 
coaling  period,  and  thereafter,  be  left  without  further 
consideration.  For  now  the  coaling  does  not  progress  any 
longer  in  the  same  direction  as  the  draught,  but  rather  in  a 
more  or  less  opposite  direction.  On  the  contrary,  the 
more  the  coaling  spreads  outward  in  the  covering,  the 
more  we  must  guard  against  the  consumption  of  charcoal, 
which  takes  place  if  the  wrarm  steam  and  gases  developed 
by  the  coaling  process,  on  their  way  out,  pass  places  where 
the  coaling  has  just  been  completed,  and  where  there  is 
for  this  reason  found  red-hot  charcoal.  This  may  be  pre- 
vented by  making  the  dust  as  tight  and  impenetrable  as 
possible,  and  by  making  with  a  stick  so-called  smoke-vents 
for  the  escape  of  the  volatile  substances  produced  by 
coaling.  These  smoke-vents  should  be  made  on  the  sides 
of  the  meiler  a  little  below  the  place  where  the  coaling  is 
principally  progressing.  Finally,  it  is  one  of  the  most 
important  rules  that  th$  temperature  be  kept  as  low  as 
possible. 

Regular  Progress  and  Care  of  Meiler. 
If  the  meiler  has  not  been  covered  sufficiently  the  work 
may  now  begin  by  putting  the  required  amount  of  dust  on 
the  covering,  and  packing  the  dust   well  and  carefully 


HAND-BOOK   FOR   CHARCOAL   BURNERS. 

down,  especially  on  the  upper  part  of  the  covering,  over 
and  round  about  the  chimney.  Sometimes,  if  the  dust  is 
very  loose  and  dry,  it  is  necessary  to  sprinkle  the  covering 
with  water,  in  order  to  make  it  tight.  When  this  is  done, 
or  while  it  is  being  done,  the  smoke- vents  just  mentioned 
above  are  made,  which  is  called  by  the  collier  giving 
"  the  meiler  a  smoke"  These  vents  are  usually  made  1 
to  2  feet  below  the  brow  and  about  2  feet  apart.  The 
most  important  duties  of  the  collier  during  this  second 
period  of  coaling  are  further :  to  watch  carefully  all  the 
signs  of  coaling  and  in  accordance  therewith  regulate 
properly  both  the  smoke- vents  and  the  canal  openings, 
which,  although  diminished  in  number  and  size,  are  con- 
tinued from  the  first  coaling  period.  The  collier  must 
give  these  smoke-vents  and  canal  openings  proper  size  and 
situation,  and  must  move  and  change  them  according  to 
the  progress  of  coaling,  the  weather,  the  quality  of  the 
hearth,  etc.  He  must  do  all  this  in  order  that  the  coaling 
process  may  spread  as  uniformly  as  possible  to  all  sides 
from  the  centre  of  the  covering,  and  in  order  that  the  tem- 
perature in  the  meiler  may  not  grow  too  high. 

If  he  succeeds  well  in  this,  to  which  also  belongs  proper 
care  of  the  dust  covering,  then  he  has  scarcely  anything 
more  to  do  than  possibly  to  take  off  the  cap  of  the  chim- 
ney once  or  twice  a  day  and  fill  in  with  more  fuel. 

The  rules  for  making  the  smoke-vents  will  be  about 
the  same  as  those  heretofore  given  in  regard  to  the  canal 
openings,  namely,  that  less  or  no  smoke-vents  should  be 
made  on  that  side  where  the  coaling  is  inclined  to  get 


HAND-BOOK   FOR    CHARCOAL    BURNERS.  75 

ahead,  which  may  often  be  easily  noticed  by  the  settling 
of  the  m.eiler,  and  that,  on  the  contrary,  more  and  larger 
smoke-vents,  sometimes  in  two  rows,  should  be  made  on 
the  opposite  side.  If  the  hearth  is  loose  and  open,  or  if 
the  billets  are  fine  and  dry,  or  if  the  weather  is  cold,  fewer 
smoke- vents  are  kept  open.  If  the  weather  is  very  windy 
the  smoke- vents  are  closed  on  the  windward  side ;  in  case 
of  a  storm,  the  whole  meiler  is  kept  closed.  All  these 
rules  need  no  other  explanation  than  that  the  colder  it  is 
the  heavier  and  denser  becomes  the  outside  air,  and  hence 
the  draught  through  the  meiler  becomes  stronger,  as  this 
depends  upon  the  difference  of  weight  between  the  outside 
air  and  the  warm  gases  and  steam  developed  in  the 
meiler. 

If  the  work  has  been  well  performed  beforehand,  and 
if  the  circumstances  generally  are  favorable,  it  may  hap- 
pen that  from  the  beginning  of  this  period  of  coaling  no 
farther  filling  is  needed,  but  that  the  meiler  gradually 
settles  according  as  the  wood  shrinks  and  is  coaled,  and 
the  collier  has  then  only  to  pack  down  and  keep  perfectly 
tight  the  dust,  so  as  not  to  permit  the  exit  of  the  draught, 
where  the  wood  has  been  coaled.  The  progress  of  the 
coaling  by  which  he  regulates  the  packing  of  the  dust 
can  be  easily  found,  if  not  by  the  settling,  then  by  the 
filling-rod. 

During  the  time  immediately  following  the  making  of 
the  smoke- vents,  while  the  latter  are  some  distance  from 
the  parts  of  the  covering,  where  the  coaling  process  is 
going  on,  the  smoke  escaping  through  these  breathing 


76  HAND-BOOK   FOR   CHARCOAL    BURNERS. 

organs  of  the  meiler  is  thick  and  opaque,  verging  on 
brown,  but  the  more  the  coaling  process  advances  down- 
ward and  outward  toward  the  brow,  the  thinner,  lighter, 
and  more  transparent  becomes  the  smoke,  and  when  this 
thin,  whirling  smoke  finally  assumes  a  bluish  color,  then 
this  is  a  sign  that  the  coaling  process  has  approached  so 
near  the  smoke-vents  that  the  last-formed  charcoal  is  not 
perfectly  protected  from  the  gaseous  products  of  coaling. 
At  this  point,  which  may  be  pretty  well  determined  by 
the  filling-rod,  the  old  smoke- vents  should  be  closed  and 
new  ones  made  lower  down,  and  then  begins  the  third  or 

*  rt 

last  period  of  coaling. 

Irregularities  in  Progress  of  Coaling. 

"We  have  now  given  the  regular  progress  of  the  process 
during  the  second  coaling  period,  which  usually  lasts  about 
three  or  four  days  ;  but  experienced,  attentive  colliers  who 
observe  closely  the  progress  of  coaling  and  understand  how 
to  estimate  the  influence  of  the  canals,  smoke-vents,  storms, 
uneven  hearths,  etc.  probably  seldom  avoid  trouble  occasion- 
ed by  irregularities  in  the  process  of  coaling.  But  still  it 
is  rather  the  exception  than  the  rule  that  a  meiler  from 
the  beginning  receives  as  constant  and  proper  care  as  it 
ought,  wherefore  it  also  quite  frequently  happens  (as  has 
been  stated  in  describing  the  first  coaling  period)  that  the 
coaling  does  not  progress  uniformly,  but  goes  in  one  direc- 
tion from  the  centre  sooner  than  in  another.  It  has  already 
been  stated  what  we  then  have  to  do,  namely,  in  the  first 
place,  by  packing  down  the  dust  harder  on  the  side  where 


HAND-BOOK   FOR    CHARCOAL   BURNERS.  77 

the  coaling  progresses  too  rapidly,  and  loosening  it  on  the 
opposite  side,  try  to  restore  the  equilibrium  ;  if  this  does 
not  produce  the  desired  result  then,  in  the  second  place,  by 
large  canal  openings  on  the  latter  side  and  blind  coaling 
on  the  former  make  the  coaling  process  go  back  to  the 
centre  ;  and  in  the  third  place,  take  the  covering  off  above 
the  place  in  question,  fill  the  vacuum  made  by  consumption 
of  charcoal  carefully  with  new  wood  and  then  cover  it  well 
again  by  packing  on  tight  new  dust. 

But  when,  in  spite  of  all  these  efforts,  the  coaling  will 
not  be  brought  back  to  its  place,  but  on  the  contrary  advan- 
ces more  toward  the  side  of  the  meiler,  which  then  shows 
that  consumption  of  charcoal  near  the  hearth  has  spread 
considerably,  then  there  is  nothing  else  to  do  than  by 
increasing  the  canal  openings  on  the  side  attacked,  to  try  to 
hasten  the  coaling  process  thither,  until  it  reaches  the  foot 
of  the  meiler,  or,  as  we  say,  "  until  the  fire  breaks  out  " 
When  this  is  done,  all  hollow  places  are  packed  well  down, 
where  the  coaling  has  been  done  and  any  farther  filling  is 
not  required.  The  smoke-vents  are  closed,  and  on  the 
opposite  side,  as  deep  as  possible,  three  or  four  canals  are 
opened,  while  all  the  old  ones  are  closed,  in  order  that  the 
fire  may  in  this  manner  be  drawn  back,  and  in  this  way 
the  meiler  is  managed  about  like  the  Yermeland  meiler 
described  below,  until  the  coaling  on  this 'side  also  gets 
into  lively  operation,  and  the  meiler  begins  to  settle.  The 
smoke-vents  and  canals  are  opened  alike  all  the  way  round, 
where  the  'meiler  is  not  yet  coaled. 

During  the  whole  process  of  coaling  the  meiler  should 


78         HAND-BOOK  FOE  CHARCOAL  BURNERS. 

never  be  left  without  care,  in  order  that  cracks  and  other 
openings  may  not  be  formed,  for  these  always  produce 
consumption  of  charcoal.  The  falling  clown  of  the  dust 
in  a  small  spot  or  a  small  hole  in  the  covering  may  easily 
cause  the  loss  of  a  great  amount  of  charcoal,  besides  mak- 
ing the  charcoal  in  its  immediate  proximity  of  a  loose  and 
poor  quality. 

If  the  hearth  slopes  toward  one  side,  or  if  the  meiler  is 
situated  on  the  slope  of  a  hill,  then,  as  the  draught  always 
is  strongest  from  the  valley  side,  the  coaling  should  from 
the  beginning  be  drawn  somewhat  toward  the  opposite  side, 
for  in  this  manner  uniformity  in  the  farther  progress  of 
coaling  is  most  easily  secured. 

THE    THIRD    PERIOD    OF    COALING. 

Condition  of  Meiler  at  Beginning  of  Third  Coaling 
Period. 

The  third  or  last  period  of  coaling,  in  which  it  especially 
progresses  from  the  covering  outward  along  the  billets, 
but  at  the  same  time  also  from  the  lower  parts  of  the 
meiler,  may  be  assumed  to  begin,  when  the  covering  has 
been  coaled,  that  is  to  say,  when  the  coaling  has  reached 
the  brow  of  the  meiler.  The  meiler,  which  has  now  settled 
considerably,  if  no  irregularities  have  taken  place,  has 
about  the  appearance  presented  in  Figure  3. 

Half  of  its  volume  consists  of  a  well  settled  mass  of  char- 
coal, having  the  form  of  an  inverted  frustum  of  a  cone, 
the  base  containing  more  or  less  charcoal.  The  rest  of  the 


HAND-BOOK   FOR   CHARCOAL   BURNERS.  79 

meiler  is  still  wood.  Near  the  charcoal  this  wood  is  per- 
fectly dry,  and  contains  some  brands  and.  some  half -charred 
billets ;  but  the  farther  out  and  down  it  is  situated  the 


Fig.  3. 

more  water  it  contains,  and  at  the  foot  of  the  meiler  it  is 
yet  quite  green  and  sour. 

The  Care  of  the  Meiler. 

It  is  now  clear  that  by  making  the  canal  openings  and 
smoke-vents  of  the  proper  size  and  number,  and  by  gradu- 
ally moving  the  smoke-vents  down,  so  that  the  smoke  al- 
ways may  have  its  exit  somewhat  below  the  coaling  pro- 
cess, and  by  observing  generally  the  rules  laid  down  hereto- 
fore, the  collier  has  it  in  his  power  to  protect  almost  per- 
fectly the  charcoal  already  formed  from  immediate  contact 
as  well  with  the  air  as  with' the  gaseous  substances  develop- 
ed by  the  coaling  process,  and  also  to  keep  the  meiler  in 
proper  coaling  temperature.  Of  course  he  must  still  and 
even  to  the  end  of  the  coaling  look  out  that  the  latter  may 


80  HAND-BOOK   FOR    CHARCOAL    BURNERS. 

progress  uniformly  on  all  sides,  and  that  the  tire  does  not 
get  to  one  side  sooner  than  to  the  other.  This  irregulari- 
ty, always  causing  some  loss  of  charcoal,  is  of  less  impor- 
tance the  nearer  the  coaling  approaches  the  foot  of  the 
meiler. 

No  fillings  are  now  needed,  for  in  the  same  degree  as 
the  billets  shrink  and  coal  they  settle  by  their  own  weight, 
Still  the  collier  must  not  neglect  to  pound  down  with  his 
shovel  all  coaled  places  and  then  pack  the  dust  well  down, 
which  now  frequently  needs  dampening  in  order  to  be  able 
to  give  the  necessary  protection. 

During  the  last  part  of  the  coaling  process  the  collier 
must  notice  carefully  the  color  and  other  qualities  of  the 
smoke,  and  move  and  regulate  the  smoke- vents  according- 
ly. It  has  already  been  stated  that  the  smoke-vents  here- 
tofore made  near  the  brow  must  be  moved  down,  when  the 
covering  is  coaled,  that  is  to  say  at  the  beginning  of  the 
third  coaling  period.  When  this  is  done,  and  if  the  smoke- 
vents  are  put  in  the  proper  place,  about  ten  inches  below 
the  line  dividing  the  charcoal  and  wood  (the  place  can  be 
found  by  the  filling-rod),  and  between  the  former  smoke- 
vents,  the  smoke  will  in  the  beginning  be  again  thick  and 
puffy,  of  a  grayish  white  color  and  strong  smell,  but  the 
more  the  coaling  progresses  downward  and  approaches  the 
new  smoke-vents,  the  whiter  and  thinner  the  smoke  grows 
again.  When  it  afterwards  assumes  a  bluish  color  mixed 
with  white,  the  smoke-vents  should  be  made  smaller,  in 
order  that  the  draught  may  not  become  too  strong ;  and 
when  the  smoke  finally  becomes  light  blue,  the  time  has 


HAND-BOOK    FOE    CHARCOAL   BURNEKS.  81 

come  to  close  the  smoke-vents  entirely  and  open  new  ones 
farther  down. 

And  so  the  smoke-vents  are  moved,  time  after  time,  far- 
ther and  farther  down  toward  the  foot  of  the  meiler,  ob- 
serving, as  has  been  stated  many  times,  that  in  all  those 
places  where  the  wood  is  coaled,  whether  it  be  in  the  cov- 
ering near  the  brow  of  the  meiler,  or  farther  down,  the 
covering  mnst  be  packed  down  without  delay,  in  order  to 
prevent,  as  far  as  possible,  draught  and  the  falling  down 
of  dust. 

If  the  new  smoke- vents  be  made  too  far  below  the  coal- 
ing process,  it  easily  happens  that  the  coaling  from  the 
centre  of  the  meiler  outward  proceeds  too  rapidly,  so  that 
the  fire  breaks  out  at  some  point  below  before  the  coaling 
from  above  has  reached  this  same  point.  The  smoke  then 
assumes  a  brownish  color,  is  very  thick  and  opaque,  and  is 
called  "brand-smoke"  or  "dangerous  smolce"  because  the 
colliers  know  that  it  produces  loss  of  charcoal.  For  now 
the  air  must  pass  through  charcoal  already  formed,  which 
is  easily  consumed,  in  order  to  reach  the  uncoaled  wood 
above :  for  obvious  reasons,  a  good  share  of  this  wood  will 
make  only  poor  charcoal  and  brands. 

The  more  rapid  or  slow  progress  of  coaling  depends 
principally  upon  the  size  and  number  of  the  smoke-vents, 
and  this  must  be  left  to  the  judgment  of  the  collier,  who 
must  bear  in  mind  that  the  larger  and  drier  the  billets,  the 
longer  time  for  coaling  is  required. 

Some  authors,  and  among  these  Uhr,  require  two  rows 

of  smoke-vents,  some  distance  from  each  other,  but  this 
4* 


82  HAND-BOOK   FOR   CHARCOAL    BTTRNEJRS. 

cannot  be  generally  recommended,  since  then  it  readily 
happens  that  charcoal  still  glowing  is  exposed  to  injurious 
contact  with  the  air  and  meiler-  smoke. 

When  the  coaling  by  moving  down  the  smoke- vents, 
which  should  be  gradually  increased  in  number,  reaches 
the  middle  of  the  lower  part  of  the  meiler,  the  number 
of  the  canal  openings,  which  has  heretofore  been  small, 
should  be  increased.  If  the  coaling  has  proceeded  regu- 
larly, these  canals  are  opened  uniformly  all  the  way  round, 
6  to  8  feet  apart ;  but  if  the  coaling  is  uneven,  more  ca- 
nals should  be  opened  on  the  side  where  the  coaling  is 
behind.  These  openings  are  moved  and  made  larger  or 
smaller,  according  to  the  demands  of  the  coaling,  and  to- 
ward the  close  their  number  is  increased  still  more,  so 
that  they  will  not  be  more  than  2  to  3  feet  apart.  For 
the  lower  part  of  the  meiler  needs  a  stronger  draught,  the 
wood  near  the  hearth  always  being  greener  and  sourer. 
Yet  even  now  we  must  take  care  not  to  go  too  far  in  open- 
ing canals,  but  only  so  far  that  the  coaling  progresses 
freely  and  unhindered  without  going  too  fast.  Finally, 
most  of  the  dust  is  shovelled  off  the  ends  of  the  billets,  in 
order. to  facilitate  a  more  even  coaling  of  the  exterior. 
When  the  fire  appears  round  about  the  foot  of  the  meiler, 
the  coaling  is  done.  Now  the  exterior  brands  at  the  foot 
are  removed,  after  which  this  part  of  the  meiler  is  covered 
again  with  newly  sifted  dust,  the  whole  heap  of  charcoal 
is  packed  well  and  left  to  cool. 

If  the  coaling  has  been  regular  from  beginning  to  end, 
the  meiler  will  settle  uniformly  on  all  sides,  and  the  fire 


HAND-BOOK    FOR   CHAECOAL    BURNERS.  83 

will  go  out  simultaneously  everywhere  at  the  foot.  The 
meiler  preserves  during  the  whole  process  a  uniformly 
rounded  form,  which  is  the  surest  evidence  of  careful 
management  and  successful  coaling. 

If  the  work  is  done  properly  and  the  wood  is  tolerably 
dry,  it  generally  takes  about  three  weeks  to  coal  a  meiler 
large  enough  to  produce  35  Swedish  lasts  of  charcoal. 
[See  Appendix,  Note  IV.] 

Removal  of  Meiler  and  Preservation  of  the  Charcoal. 

To  the  work  of  coaling  belongs,  furthermore,  the  care 
of  the  charcoal  obtained.  It  must  be  taken  out  of  the 
meiler  and  stored  away  for  preservation.  It  is  of  great 
importance  that  this  work  be  done  well  and  carefully,  and 
still  we  may  safely  say  that  this  part  of  the  coaling  work 
is  usually  done  the  worst.  Of  course  the  removal  of  the 
meiler  may  be  done  in  more  than  one  way,  and  the  man- 
ner must  be  determined  by  the  size  of  the  meiler,  the  sea- 
son of  the  year,  local  circumstances,  etc.  It  would,  there- 
fore, be  to  no  purpose  to  prescribe  fixed  rules  for  doing 
this  or  that  part  of  the  work,  and,  in  explaining  below 
some  modes  of  procedure,  we  only  mean  to  show  how  the 
following  rules  may  be  applied  and  followed. 

The  first  thing  we  have  to  see  to  is  that  the  charcoal  is 
protected  as  w^ell  as  possible  from  consumption  by  fire. 
This  is  secured  in  the  safest  manner  by  letting  the  fire  be 
completely  extinguished  before  removing  the  meiler,  and 
sometimes^by  keeping  the  meiler  sealed,  but  as  this  is  not 


84:  HAND-BOOK    FOR   CHARCOAL    BURNERS. 

practicable  in  all  places,  and  as  tlie  manner  of  procedure 
varies  very  much,  we  will  give  it  a  separate  paragraph 
below.  In  the  following  we  will  therefore  show  how  we 
may,  as  well  as  possible,  protect  the  charcoal  from  de- 
struction by  fire,  when  the  meiler  is  removed  shortly  after 
the  coaling  is  finished. 

The  removal,  must,  however,  never  be  done  immediately 
after  the  coaling  is  finished,  \vhile  a  part  of  the  charcoal 
is  still  red  hot ;  but  the  meiler  should  always  be  left  one 
or  two  days,  although,  if  the  hearth  is  very  loose,  never 
longer.  During  this  coaling  period  the  dust  covering 
should  be  increased  and  well  packed,  in  order  that  the 
meiler  may  be  kept  as  air-tight  as  possible,  and  it  should 
never  be  left  without  care.  In  removing  the  meiler,  which 
should  not  be  done  in  windy  weather,  a  sufficient  quantity 
of  water  should  always  be  kept  at  hand  to  extinguish  the 
charcoal,  which  is  still  glowing  when  it  is  taken  out,  and 
to  dampen  the  dust,  which,  every  time  any  charcoal  is 
taken  out,  is  thrown  on  again,  to  keep  the  rest  of  the 
meiler  tight  and  free  from  draught. 

Finally,  the  charcoal  taken  out  should  not  be  stored 
away  immediately,  before  we  are  certain  that  it  does  not 
contain  any  fire.  This  can  be  seen  best  at  night,  and  hence 
the  night  is  the  best  time  for  the  kind  of  work  which  we 
are  here  describing. 

The  second  principal  rule  is :  Not  to  use  more  water 
when  we  remove  the  meiler  than  is  actually  needed  to 
quench  the  fire  in  the  burning  charcoal.  To  pour  water 
in  large  quantities  over  the  charcoal,  and  even  over  that 


HAND-BOOK    FOR    CHARCOAL    BURNERS.  85 

which  does  not  contain  any  fire,  is  very  injurious,  for  in 
that  way  we  get  sour  charcoal,  which,  on  account  of  its 
moisture,  has  less  value  than  dry  charcoal ;  besides,  it  is 
heavier  to  transport,  and  in  case  of  frost  it  freezes  and  is 
broken  down  into  dust. 

Finally,  in  the  third  place,  we  should  avoid  everything 
that  may  tend  to  injure,  break,  or  waste  the  charcoal. 
Then  in  removing  the  charcoal  we  should  not  use  a  shovel, 
but  a  light  meiler-hook,  handled  with  care,  with  a  rake  and 
a  basket  or  box.  To  hack  into  the  meiler  with  a  heavy 
meiler-hook,  and  thus  bring  the  charcoal  out,  or  to  break 
it  out  with  a  handspike,  or  other  heavy  tool,  must  be 
strictly  forbidden.  All  tramping  and  climbing  on  the  re- 
moved charcoal  should  likewise  be  avoided,  wherefore  the 
work  is  generally  done  better  by  a  few  men  than,  as  is 
often  the  case,  by  a  lot  of  men  and  boys  crowding  each 
other.  A  considerable  quantity  of  charcoal  may  be  lost, 
if  we  neglect,  before  removing  the  meiler,  to  sweep  the 
place  around  the  meiler  free  from  snow  or  dust — that  is, 
where  the  charcoal  is  to  be  put.  Removal  during  rain  or 
snow  should  only  be  done  when  absolutely  necessary. 

It  is  of  special  importance  that  the  charcoal,  as  soon  as 
we  are  sure  that  it  does  not  contain  any  fire,  be  piled  up 
and  stored  away  in  such  a  manner  that  it  is  protected 
from  bad  weather,  until  it  is  transported  to  the  place 
where  it  is  to  be  used.  Still  it  is  a  very  common  thing  to 
see  the  charcoal,  after  being  removed,  lie  the  whole  time 
under  the  open  sky  in  a  circle  around  the  hearth,  exposed 
to  all  kinds  of  weather,  by  which  it  becomes  sour,  icy, 


86  HAND-BOOK   FOR   CHARCOAL    BURNERS. 

dusty,  heavy  to  transport,  while  in  loading  much  is  lost  in 
the  snow,  or  crushed  beneath  the  horses'  feet  and  the 
wheels  of  the  wagon. 

We  will  now  give  an  illustration  of  how  these  general 
rules  may  be  applied  and  modified.  When  the  metier  has 
been  left  untouched  for  24  hours,  excepting  to  close  quick- 
ly and  carefully  all  openings  that  may  be  formed,  then 
the  dust  and  brushwood  are  taken  off  for  a  breadth  of 
about  four  feet,  after  which  the  dust,  well  cleaned  and 
separated  from  brushwood,  bark,  chips,  etc.,  is  thrown  upon 
the  charcoal  again  and  packed  down  well.  Then  another 
strip  of  the  meiler  is  treated  in  the  same  manner,  and  so 
we  continue  clear  around  the  meiler*  This  work  may  be 
done  by  one  man  in  half  a  day. 

Glowing  parts  of  the  meiler  should  be  covered  with 
fresh  dirt,  sandy  loam  if  possible,  and  the  whole  new  dust 
covering  should  be  sprinkled  with  water  as  much  as  it  will 
absorb ;  this  is  repeated  in  places  where  the  dust  dries 
again,  this  being  an  indication  that  the  fire  is  not  far  off. 

If  this  work  is  done  properly,  and  the  hearth  is  tolerably 
free  from  draught,  there  will  be  but  little  fire  left  when 
the  m,eiler  is  removed  a  day  or  two  later. 

If  we  have  two  metiers  to  remove  at  the  same  time,  then 
we  first  carefully  remove  with  hook  and  rake  one  layer  of 
charcoal  from  one  of  the  metiers,  and  the  charcoal  is  laid 
out  to  be  cooled  around  the  hearth  after  having  quenched 
with  water  those  pieces  of  charcoal  that  contain  fire.  The 
parts  of  the  meiler  that  have  in  this  manner  been  exposed 
are  recovered  with  dust,  and  the  workmen,  three  in  mun- 


HAND-BOOK  FOB  CHARCOAL  BURNERS.         87 

ber,  proceed  to  meiler  !Nb.  2,  and  treat  it  in  the  same  way. 
Afterwards  they  return  to  the  first  meiler  to  bring  the  char- 
coal removed  arid  cooled  under  cover,  whereupon  they 
bring  down  around  the  meiler  another  layer  of  charcoal, 
which  is  treated  in  the  manner  stated,  and  so  the  work 
keeps  on  interchanging  between  the  two  meilers  until  all 
the  charcoal  is  removed. 

It  is  customary  to  begin  the  removal  in  the  covering 
and  proceed  layer  after  layer  downward ;  still  we  always 
take  first  one  layer  of  charcoal  around  the  meiler.  By  the 
dust  falling  down  into  the  meiler,  when  the  removing  is 
done  from  the  top  downward,  the  fire  that  may  remain  is 
more  easily  extinguished  than  when  the  removing  proceeds 
from  the  circumference  inward. 

In  Germany  it  is  customary  after  the  coaling  process,  to 
remove  the  charcoal  from  the  covering  in  parts,  and  then 
with  a  brush-broom  sweep  dry  dust  down  into  the  charcoal 
below,  which  is  thereby  extinguished.  Then  the  meiler  is 
removed  after  a  day  or  two. 

The  charcoal  shed  should  have  a  dry  place,  and  to  save 
work  it  should  stand  near  the  hearth.  It  may  be  built  of 
common  meiler  billets  of  proper  length  and  in  such  a  way 
that  two  rows  of  posts  are  set  up  for  each  of  the  three 
walls  of  the  shed,  between  which  the  meiler  poles  are  laid. 
Each  pole  is  fastened  to  the  posts  with  a  willow  in  the 
same  manner  as  when  we  make  a  fence.  The  open  fourth 
side  is  closed  by  brands,  large  pieces  of  charcoal.  The 
walls  need  not  be  higher  than  about  3-J-  feet,  over  which 
the  charcoal  is  built  so  as  to  form  a  convex  covering,  which 


88  HAND-BOOK    FOR   CHARCOAL    BURNERS. 

is  covered  with  brushwood,  but  in  such  a  manner  that 
the  brushwood  projects  over  the  edges  of  the  walls,  and 
over  the  brushwood  we  put  dust,  as  when  we  cover  a 
meiler. 

When  we  have  put  as  much  charcoal  into  the  shed  as 
we  can  conveniently  without  breaking  the  charcoal  to 
pieces,  we  put  up  the  so-called  charcoal  ladder  with  the 
aid  of  which  we  put  up  the  rest.  These  sheds  may  also  be 
built  of  posts  and  covered  with  boards,  split  billets,  or 
spruce  bark.  One  large  shed  is  better  than  two  or  more 
smaller  ones :  the  less  roof  the  better. 

Sealing  of  the  Meiler. 

It  has  already  been  mentioned  above,  that  instead  of  re- 
moving the  meiler  shortly  after  it  has  been  cooled,  we 
sometimes  let  it  become  entirely  extinguished,  which  is 
done  by  keeping  it  perfectly  closed  and  air-tight.  The 
colliers  call  this  sealing  the  meiler ',  and  it  is  done  in  the 
following  manner :  When  we,  24  hours  after  the  coaling 
of  the  meiler,  have  examined  the  chimney  and  taken  up 
the  uncoaled  wood,  if  any  is  found,  the  covering  is  removed 
as  stated  above,  and  clean  line  dust  is  put  on  the  charcoal 
without  any  brushwood  between.  This  dust  is  put  on  4 
to  6  inches  thick,  but  thickest  near  the  foot,  and  packed 
carefully  everywhere  ;  after  which  the  whole  meiler  is  cov- 
ered 1  to  2  inches  thick  with  dust  consisting  of  fine  sand 
free  from  stones  and  mixed  with  clay  if  possible,  such  as 
will  not  run  down  when  it  gets  dry,  but  sticks  together 
about  like  form-sand.  The  meiler  is  now  packed  a^ain 


HAND-BOOK   FOR   CHARCOAL    BURNERS.  89 

and  whipped  with  a  rod  ;  after  which  it  is  pounded  with 
shovels  which  have  been  wanned  somewhat  beforehand  so 
that  the  dust  will  not  stick  to  them.  When  the  covering 
of  the  meiler  has  become  tight  by  this  operation,  the 
watering  begins,  for  which  we  use  flat  wooden  scoops  with 
long  handles.  The  water  is  thrown  from  all  sides  high 
above  the  covering  of  the  meiler p,  in  order  that  it  may  fall 
like  a  heavy  rain  upon  the  meiler.  We  continue  this 
operation  so  long  as  the  dust  is  able  to  absorb  or  until  the 
water  begins  to  run  down  the  sides  ;  for  this  8  to  10 
buckets  of  water  are  used  according  to  the  size  of  the  mei- 
ler. This  watering  is  renewed  as  soon  as  we  notice  any 
part  of  the  meiler  begins  to  dry.  During  the  flrst  24  hours 
watering  is  needed  at  least  three  times,  during  the  second 
and  third  days  two  each,  and  after  that  generally  about 
once  a  day.  If  heavy  rain  falls  we  will  have  to  regulate 
the  watering  accordingly.  After  the  seventh  day  we  may 
try  to  omit  the  watering  entirely,  but  if  we  then  discover 
any  place  where  the  dust  is  inclined  to  dry,  the  watering 
must  be  renewed  again.  When  8  to  12  days  have  elapsed, 
the  meiler  is  usually  entirely  extinguished,  but  if  we 
notice  that  it  is  still  quite  warm,  which  is  indicated  by  the 
vapor  rising  from  the  covering,  then  we  know  that  from 
some  defect  in  the  hearth,  or  some  negligence  in  the  work, 
the  heat  is  increasing ;  in  which  case  the  meiler  should  be 
removed  immediately. 

It  is  of  great  importance  that  the  first  watering  should 
be  copious,  that  the  meiler  should  be  constantly  kept  per- 
fectly air-tight,  and  that  cracks  should  be  closed  immedi- 


90  HAND-BOOK   FOR   CHARCOAL   BURNERS. 

atelj.  Generally  it  is  regarded  as  improper  to  pour  water 
into  the  meiler,  and  undoubtedly  the  charcoal  may  be  in- 
jured by  so  doing.  Still  it  might  do  no  harm  to  pour 
down  a  pailful  here  and  there  into  openings  made  in  the 
covering  and  extending  about  2  feet  above  the  hearth. 
This  is  not  for  the  purpose  of  extinguishing  glowing  char- 
coal, but  for  the  purpose  of  filling  the  meiler  with  steam, 
which  cools  and  smothers  all  moderately  hot  fire  that  may 
be  thus  reached.  Besides,  if  the  fire  is  sustained  in  some 
single  spot,  which  is  indicated  by  the  drying  of  the  dust, 
it  may  be  good  to  make  a  few  holes  around  this  spot,  and 
pour  a  little  water  down  each  hole.  But,  as  is  often  done, 
to  pour  water  by  the  bucket  down  into  the  meiler  through 
a  few  openings  is  certainly  injurious,  for  thereby  a  part 
of  the  charcoal  is  drenched,  and  the  places  where  the  water 
runs  down  become  to  that  extent  cooled  that  no  steam  is 
formed,  but  the  fire  may  glow  and  burn  near  by  such  a 
place  drenched  with  water. 

In  Sodermanland  some  colliers  use  the  following  method 
of  sealing  the  meiler  :  The  covering  is  partly  removed, 
by  which  the  dry  dust  runs  down  among  the  charcoal  be- 
neath and  helps  to  tighten  the  meiler.  Afterwards  new 
dust  is  thrown  upon  the  meiler,  and  well  packed.  Then 
there  is  made,  at  least  2  feet  from  the  hearth,  in  the  dust 
clear  to  the  charcoal,  a  horizontal  furrow  about  15  feet 
long.  In  this  furrow  water  is  poured,  after  which  dust  is 
raked  down  into  it  and  stirred  up  with  the  water,  so  that 
it  forms  a  puddling  as  it  were  down  to  the  foot  of  the 
meiler  of  one  to  two  feet  thickness.  Then  we  continue  in 


HAND-BOOK   FOE   CHARCOAL   BURNERS.  91 

the  same  manner  upward  to  near  the  middle  of  the  cov- 
ering, where  one  foot  thickness  of  the  puddling  is  suffi- 
cient. Now  we  make  another  furrow  about  15  feet  long 
at  least  two  feet  from  the  hearth,  which  is  treated  in  the 
same  manner  from  the  foot  upward,  and  so  on  around 
the  meileTj  until  it  everywhere  to  the  middle  of  the  cover- 
ing has  received  such  a  thickness  of  puddling,  but  we 
must  see  that  the  places  where  these  furrows  connect,  be- 
come perfectly  tight.  As  a  matter  of  course,  dust  con- 
sisting of  clear  sand  mixed  with  clay  should  be  on  hand 
to  be  thrown  upon  the  metier.  If  there  is  water  close  by, 
then  six  men  can  in  one  day  seal  in  this  way  a  meiler  of 
common  size. 

If  neither  heat,  dampness,  nor  hot  air  is  noticed,  when 
we  open  a  hole  in  the  covering,  then  we  may  be  certain 
that  the  meiler  is  extinguished.  When  it  becomes  per- 
fectly cool,  of  which  the  best  proof  is  that  the  dust 
freezes,  or  that  the  snow  remains  on  the  covering  without 
melting,  the  dust  should  be  cleared  away  in  a  broad  strip 
around  the  foot.  If  we  neglect  this,  the  work  in  taking 
away  the  charcoal  will  be  considerably  greater,  and  it  will 
then  be  very  difficult  to  secure  the  charcoal  frozen  fast  in 
the  dust  along  the  edge  of  the  meiler  hearth. 

This  method  of  sealing  the  meiler,  and  afterwards 
letting  it  remain  undisturbed,  until  the  charcoal  is  taken 
up  directly  from  the  hearth,  has  its  great  incontestable 
advantages.  This  is  the  method  pursued  in  Ostergotland 
and  Smaland. 

The  usually  difficult  work  of  removing  the  meiler  now 


92  HAND-BOOK   FOR    CHARCOAL    BURNERS. 

becomes  comparatively  easy ;  the  charcoal  is  in  every  way 
better  protected  from  combustion,  wet,  freezing,  etc.  In 
removing  the  meiler  in  the  usual  manner  and  in  the  hand- 
ling of  the  charcoal  connected  therewith,  never  less  than  a 
tenth  part  of  the  charcoal  is  lost ;  and  this  loss  may  reach 
20  per  cent,  or  more.  Finally  it  should  be  noted  that, 
even  though  the  meiler  should  remain  standing  the  whole 
year,  still  the  charcoal  protected  by  the  dust  will  not  be 
damaged. 

But  in  order  that  this  method  of  sealing  may  be  suc- 
cessful the  hearth  must  be  tight  and  free  from  draught, 
the  meiler  well  coaled,  and  great  accuracy  and  care  must 
be  taken  in  packing  and  watering  the  dust.  Furthermore 
it  is  necessary  that  there  should  be  an  abundance  of  water 
on  hand,  and  sand  fit  for  covering  near  by.  The  coaling 
should  be  completed  in  the  fall,  before  the  severe  night- 
frosts  set  in.  The  freezing  loosens  the  dust,  and  then  it 
is  quite  impossible  to  make  it  sufficiently  tight  and  pro- 
tective. Meilers  containing  damaged  wood  or  asp  are 
difficult  to  seal. 

Although  this  method  of  sealing  is  generally  used  in 
certain  provinces,  and  there  seldom  fails,  yet  it  has  not 
found  favor  and  adoption  in  other  districts  where  it  has 
been  tried.  It  has  been  claimed  that  the  charcoal  obtained, 
although  apparently  of  the  best  quality,  has  not  been  so 
strong  as  that  removed  in  the  usual  manner,  and  is  more 
cracked  by  the  fire  than  the  former. 

The  real  facts  in  this  case  cannot  be  accurately  ascer- 
tained except  by  experiments  on  a  large  scale. 


HAND-BOOK   FOR   CHARCOAL    BURNERS.  93 


2.  THE  GERMAN  STANDING  MEILER. 

Preparation  of  the  Wood. 

Nearest  the  Swedish  standing  meiler,  both  in  respect  to 
the  manner  of  raising  the  billets  and  in  respect  to  the  pro- 
gress and  care  of  the  coaling,  is  the  German  standing 
meiler,  with  short  split  billets,  or  as  it  is  called,  the  Harz 
meiler  (see  Fig.  4),  which  is  mostly  used  in  Germany,  but 
has  also  been  adopted  in  some  parts  of  Sweden.  The 
billets  are  cut  in  lengths  of  4  to  5  feet,  and  split  if  they 
have  a  diameter  of  5  to  6  inches  or  more.  If  wood  pre- 
pared in  this  way  is  corded  during  the  winter,  it  will  be 
dry  enough  in  April  to  be  hauled  to  the 'hearth,  where  it 
is  piled  up  in  an  open  heap  for  further  seasoning,  until 
the  meiler  is  to  be  raised.  This  way  of  preparing  the 
wood  is  undoubtedly  the  best  method  known,  for  the  ad- 
vantage of  having  wood,  thoroughly  seasoned,  of  uniform 
size,  without  intermixture  of  thick  half  seasoned  blocks,  is 
of  itself  great;  in  addition  to  this,  short  billets  make  it 
possible  to  utilize  even  small  and  crooked  wood,  and 
during  the  process  of  coaling  the  meiler  will  settle  easier, 
whereby  the  work  of  coaling  will  be  considerably  facili- 
tated, and  neither  so  large,  nor  so  frequent  fillings  required. 
It  is  therefore  probable  that  the  Harz  method  will  gain 
ground  in  Sweden  as  the  value  of  charcoal  increases; 
especially  as  the  care  of  this  kind  of  meiler  does  not  differ 
materially  from  that  of  the  common  Swedish  standing 
meiler  on  horizontal  hearth. 


94:  HAND-BOOK   FOR   CHARCOAL    BURNERS. 

As  Fig.  4  shows,  the  Harz  meiler  consists  of  2  (sometimes 
3)  tiers  of  billets,  raised  one  above  the  other,  and  a  covering 
of  short  small  wood.  The  meiler  is  raised  on  a  horizontal 
hearth  somewhat  convex,  and  may  be  bnilt  with  or  without 
a  chimney  or  drum  for  kindling.  If  we  have  a  chimney, 
the  building  and  coaling  will  be  done  principally  in  the 
same  manner  as  that  of  the  Swedish  standing  meiler  de- 
scribed above,  excepting,  however,  what  will  hereafter  be 
explained  about  foot-blocks  and  the  creation  of  strong 
draught  at  the  foot  of  the  meiler. 


FIG.  4. 

If  we  do  not  have  a  chimney,  which  is  the  most  common 
and  most  desirable,  the  kindling  is  done  in  a  kindling 
canal  made,  near  the  hearth,  by  erecting  in  the  centre  of 
the  hearth  a  straight  pole  firmly  fixed  and  well  supported; 
against  this  we  put  up  edgewise  two  slabs  or  split  brands, 
resting  against  poles  stuck  into  the  ground,  and  thus  form 
a  triangular  space.  In  this  space  we  put  a  wooden  crotch, 
4  to  5  inches  in  diameter,  after  which  we  begin  to  raise 
the  billets,  observing  that  none  of  them  must  rest  on 


HAND-BOOK   FOR    CHARCOAL    BURNERS.  95 

the  crotch,  but  as  the  raising  progresses,  it  is  drawn  out 
horizon  tally,  until  the  exterior  layer  is  put  up,  when  it  is 
taken  away,  and  the  kindling  canal  is  formed.  During 
the  first  part  of  the  raising,  we  throw  on  the  two  slabs 
either  birch  bark  or  dry  wood  and  finely  split  brands,  as 
much  as  is  needed  to  kindle  the  driest  meiler  billets,  which 
are  placed  immediately  around  the  centre  pole  of  the 
meiler.  As  there  will,  of  course,  always  be  some  draught 
out  along  this  canal,  it  should  not  be  made  on  a  side  to 
which  we  know  or  believe  beforehand  that  the  fire  will 
have  a  tendency  to  progress.  Hence  it  should  not  be  put 
on  the  valley  side,  nor  on  that  side  from  which  the  most 
violent  and  persistent  winds  usually  blow. 

liaising  and  Thatching  of  the  JkTeiler. 

The  raising  of  the  billets  is  done  about  in  the  same 
manner  as  in  the  common  Swedish  standing  meiler.  Both 
tiers  of  billets  should  be  raised  at  the  same  time,  one 
above  the  other.  Above  the  place  of  kindling,  the  meiler 
is  made  quite  tight  with  the  largest  billets,  since  it  is  our 
object  to  keep  the  fire  in  the  lower  tier  as  long  as  possi- 
ble. As  the  heat  usually  works  upward,  and  the  warm 
gases  rise,  the  larger  billets  should  be  placed  in  the  second 
tier. 

In  the  next  place,  for  the  purpose  of  facilitating  the 
coaling,  the  split  side  of  the  billets  should  generally  be 
turned  inward ;  that  is  to  say  when  the  proper  tightness 
of  the  meiler  does  not  now  and  then  make  it  necessary  to 
turn  the  billets  otherwise.  All  open  spaces  are  filled  with 


96  HAND-BOOK   FOR   CHARCOAL    BURNERS. 

small  wood  and  twigs.  In  metiers  made  of  short  billets  it 
is  always  less  difficult  to  make  the  meiler  sufficiently  tight 
at  the  foot  without  making  it  too  steep ;  in  order  to  make 
the  dust  keep  its  place  better,  we  may  make  the  upper 
tier  slope  more  than  the  lower  one. 

Finally,  the  covering  is  made  of  wood  and  twigs  two  to 
three  feet  long,  after  which  the  meiler  is  thatched  with 
brushwood  as  usual. 

Another  method  of  making  these  meilers,  so  as  to  keep 
the  heat  longer  at  the  hearth  and  hasten  the  heating  of 
the  meiler,  is,  when  the  lower  tier  has  obtained  a  diameter 
of  about  6  feet,  to  throw  on  as  much  line  charcoal  as  can 
be  made  to  keep  its  place,  and  to  lay  on  this  charcoal 
short,  thick  pieces  of  wood  as  high  as  the  second  tier  is  to 
reach.  Such  a  sacrifice  of  not  more  than  ten  cubic  feet 
of  small  charcoal  is  very  profitable,  for  the  wood  then 
dries  better  and  the  coaling  begins  sooner,  wherefore  less 
wood  is  consumed  than  when  no  charcoal  is  used.  The 
other  raising  is  done  in  the  usual  way. 

When  the  'meiler  has  been  thatched  with  brushwood, 
we  lay  round  the  foot  of  the  meiler  the  so-called  foot- 
llocks,  which  consist  of  common  meiler  billets,  or  still  bet- 
ter, of  boards  procured  especially  for  this  purpose,  which 
are  laid  upon  stones  or  stumps  6  to  12  inches  high.  The 
purpose  of  these  is  to  sustain  the  dust  and  to  produce  a 
strong  draught  out  along  the  foot  of  the  meiler,  both 
during  kindling  and  the  final  coaling. 

The  dust  is  put  on  in  the  usual  way,  except  that  the 
foot  of  the  meiler  is  for  the  present  left  uncovered,  and  a 


HAND-BOOK   FOE   CHARCOAL    BURNERS.  97 

strip,  3  to  4  feet  wide  around  the  brow  is  left,  either  en- 
tirely without  dust  or  is  furnished  with  a  thin  loose  dust 
covering  about  3  inches  thick. 

Watching  of  the  Meiler. 

When  the  strip  above  referred  to  is  left  open  we  say  the 
meiler  is  kindled  with  open  brow,  and  when  covered  that 
the  kindling  is  done  blind.  The  meiler  is  kindled  blind  in 
the  following  manner :  In  still  weather,  early  in  the  morn- 
ing if  possible,  some  burning  birch-bark  or  a  kindled  torch 
fastened  to  the  end  of  a  rod  is  pushed  in  through  the 
kindling  canal  under  the  combustible  substances  hereto- 
fore placed  in  the  centre  of  the  meiler.  When  these  have 
caught  fire  the  rod  is  drawn  out,  and  'the  kindling  canal 
is  closed  with  a  few  pieces  of  wood  and  a  little  loose  dust. 
After  ten  to  fifteen  minutes,  as  soon  as  we  may  be  certain 
that  the  fire  does  not  go  out,  we  begin  to  cover  with  dust 
under  the  foot-blocks  here  and  there,  and  after  half  an 
hour  or  a  little  more  the  whole  meiler  is  closed,  and  kept 
so  about  two  days,  after  which  time  smoke- vents  are 
opened,  and  the  coaling  progresses  in  the  usual  manner. 
Sometimes  fillings  are  made  as  required,  the  first  filling 
usually  taking  place  in  the  evening  of  the  same  day  as  the 
kindling  is  done,  and  then  two  or  three  times  a  day, 
according  to  the  dryness  of  the  billets.  If  the  billets  are 
quite  dry,  and  work  properly  done  from  the  beginning,  it 
may  happen  that  in  all  only  4  to  5  fillings  are  needed. 
If  we  think  the  fire  is  too  low,  we  can  remedy  it  by  open- 
ing a  few  smoke-vents  in  the  covering  sooner. 
5 


98  HAND-BOOK   FOR    CHARCOAL    BURNERS. 

If  the  meiler  is  to  be  kindled  with  open  brow,  which  in 
respect  to  bringing  the  fire  to  the  centre  of  the  meiler  is 
done  in  the  manner  stated  above,  it  is  of  still  greater  im- 
portance to  select  perfectly  still  weather ;  after  which  the 
covering  with  dust  must  be  done  with  great  care.  The 
steam  must  have  a  free  exit,  but  too  much  air  and  too 
much  heat  are  just  as  injurious  as  the  hasty  covering  of 
the  meiler  with  dust.  We  can  only  find  out  what  is  proper 
to  do  after  determining  accurately  the  degree  of  dryness 
and  other  qualities  of  the  billets. 

In  the  beginning  there  appears  a  thick,  gray,  and  moist 
smoke,  which  after  an  hour  or  so  assumes  a  brownish-yel- 
low color,  whirls  rapidly  upward,  and  emits  an  offensive 
smell.  Now  is  the  time  to  begin  to  cover  the  meiler  with 
dust  at  the  brow.  This  is  done  in  the  following  manner: 
"We  first  cover  the  places  that  smoke  the  most,  continue 
then  in  rows  and  different  places,  beginning  first  on  the 
windward  side,  until  it  is  perfectly  covered  at  the  brow ; 
after  which  the  opening  underneath  the  foot-blocks  is 
closed  in  the  manner  described  above.  When  this  is  done 
the  dust  is  evenly  distributed  and  packed  down  with  the 
rod,  so  that  the  meiler  everywhere  may  be  as  tight  and 
close  as  possible.  The  filling  hole  is  opened  in  the  course 
of  the  day,  sooner  if  the  billets  are  small  and  dry,  later  if 
they  are  large  and  green,  and  is  filled  in  the  usual  way 
with  dry  wood  or  charcoal  and  brands.  In  the  course  of 
the  second  day  a  few  smoke-vents  are  opened  around  the 
covering:  after  this  the  coaling  is  done  as  in  the  common 
Swedish  meiler. 


HAND-BOOK    FOR    CHARCOAL   BURNERS.  99 

The  manner  of  kindling  here  described  makes  the  work 
easier,  and  has  besides  the  following  advantages :  a  large 
amount  of  the  dampness  escapes  partly  at  the  brow  and 
partly  below  the  foot-blocks, — metiers  treated  in  this  way 
are  less  apt  to  explode, — the  wood  dries  faster,  and  hence 
the  German  standing  metier,  especially  if  kindled  with 
open  brow,  does  not  require  so  long  time  for  coaling  as 
the  common  Swedish  metier.  If  we  compare  the  two 
methods,  we  will  find  that  Hind  kindling  is  better  for  dry 
and  small  wood,  and  that  kindling  with  open  brow  is 
better  for  large  and  green  billets.  The  last  named  me- 
thod is  always  more  violent,  and  requires  at  least  two 
persons  to  put  on  the  dust  fast  enough,  a  work  that  must 
not  be  done  too  rapidly,  however,  for  then  the  metier 
may  begin  to  explode. 

A  person  igniting  a  metier  of  this  kind  for  the  first 
time  will  hear  with  a  certain  uneasiness  a  violent  crackling ; 
he  will  naturally  suppose  that  there  is  danger  ahead,  and 
that  a  large  portion  of  the  wood  is  burning  up.  But  there 
is  no  necessity  for  fear.  The  large  wood  in  the  centre  of 
the  upper  tier  does  not  become  ignited  so  fast,  and  is  not 
consumed  more  rapidly  than  is  necessary  to  bring  the  coal- 
ing into  operation.  A  high  temperature  near  the  place  of 
kindling  cannot  be  otherwise  than  advantageous,  as  long 
as  scarcely  anything  but  steam  is  made  to  evaporate  from 
the  billets  immediately  around  it,  while  we  may  afterwards, 
by  completely  closing  the  metier  with  dust,  lower  the  tem- 
perature sufficiently  to  make  the  coaling  progress  quietly, 
with  a  properly  regulated  heat.  It  has  been  tried  to  kin- 


100  HAND-BOOK   FOR   CHARCOAL    BURNERS. 

die  even  other  meiler  s  with  longer  and  larger  wood  in  the 
manner  described,  and  it  has  always  been  found  profitable. 
The  care  of  the  German  meiler  is  in  other  respects  like 
the  care  of  the  Swedish  meiler  described  above,  observing 
only  that,  the  billets  generally  being  smaller  and  drier,  the 
'meiler  does  not  require  so  strong  a  draught. 

3.  THE  ITALIAN  STANDING  MEILER. 

Next  in  order  will  be  to  describe  briefly  the  so-called 
Italian  method  of  coaling,  which,  although  not  used  much 
in  Sweden,  still  is  a  good  method  in  permanent  meiler 
places,  to  which  large  quantities  of  wood  can  be  gathered, 
and  where  there  is  an  abundant  supply  of  dust,  as  is  fre- 
quently the  case  near  factories. 

The  hearth  is  made  perfectly  horizontal,  and  ought  to 
be  as  tight  and  firm  as  possible,  wherefore  it  is  also  usually 
built  of  stone  or  tiles,  and  then  covered  with  a  mixture  of 
sand  and  clay,  packed  hard. 

The  'meiler  billets  are  not  raised  immediately  upon  this 
hearth,  but  on  a  wooden  bridge,  built  the  same  width  as 
the  meiler  is  to  have.  This  bridge  (Fig.  5)  is  made  by 
laying  out  in  rays  from  the  centre  in  all  directions  of  the 
radius  billets  3  to  6  inches  thick  and  6  to  8  feet  lon^,  with 

S" 

the  tapering  end  inward,  and  so  near  together  that  their 
butt-ends  will  be  about  1£  feet  apart.  Crosswise  over 
these  billets  are  laid  old  boards  that  are  good  for  noth- 
ing else,  and  slabs  or  split  billets,  so  tight  as  to  form  as  it 
were  a  floor,  upon  which  the  billets  are  raised.  The  ob- 
vious advantage  of  this  arrangement  is  that  we  have  it  in 


HAND-BOOK   FOR    CHARCOAL    BURNERS.  101 

our  power  to  make  the  draught  from  below  as  strong  or 
light  as  the  case  may  require,  and  that  the  coaling  of  the 
meiler  itself  will  be  more  perfect,  leaving  no  brands  or 
half  charred  wood.  On  the  other  hand,  the  wooden  bridge 
with  the  billets  beneath  it  is  not  coaled,  nor  is  this  the  in- 
tention ;  but  a  part  thereof  is  only  changed  to  brands 
which  afterwards  are  used  for  kindling  the  next  meiler. 

The  billets,  6  to  7  feet  long,  large  and  not  split,  are 
raised  closely  and  carefully  in  two  tiers,  and  thereupon  is 
laid  a  covering  2  feet  high  of  small  and  short  wood.  The 
chimney  or  drum  is  made  cylindrical  by  two  strong  iron. 
rings,  one  foot  in  diameter,  put  between  and  fastened  by. 
three  poles  erected  on  the  centre  of  the  hearth ;  one 
ring  situated  about  four  feet  above  the  hearth,  and  the 
other  the  same  distance  from  the  top  of  the  meiler.  Im- 
mediately around  these  rings  and  poles  the  billets  are 
placed  upright,  but  afterwards  they  gradually  slope  in- 
ward, so  that  the  slope  of  the  exterior  layer  may  reach 
even  thirty  degrees  from  a  plumb-line,  or  as  great  as  the 
slope  of  the  Swedish  meiler  which  we  have  described. 

When  the  hearth  billets  have  been  raised,  we  raise,  by 
the  aid  of  a  crane  or  bridge  for  bringing  up  the  wood,  the 
upper  tier.  When  this  work  is  done  and  the  covering  put 
on,  the  whole  exterior  is  made  as  tight  and  smooth  as  pos- 
sible ;  this  is  a  very  important  work,  since  in  this  kind  of 
meiler  no  brushwood  or  other  material  for  an  under  layer 
of  thatching  is  used  to  prevent  the  dust  from  falling  down 
among  the  billets.  For  this  tightening  is  then  required  a 
good  supply  of  fine  split  wood  and  twigs.  The  dust  cover- 


102  HAND-BOOK    FOE    CHARCOAL    BURNERS. 

ing  is  made  two  feet  thick  around  the  lower  part  of  the 
meiler  and  one  foot  at  the  brow.  But  before  the  dust  is 
put  on,  it  should  be  carefully  raked  and  cleaned  and 
sprinkled  with  water ;  after  which,  in  putting  it  on,  which 
begins  from  below,  it  should  be  packed  and  tramped  down 
to  the  wood,  so  that  all  draught  there  may  be  shut  off  so 
far  as  possible. 


FIG.  5. 

Above  the  brow,  on  the  other  hand,  we  put  on  only  9 
inches  thick  of  perfectly  dry  and  loose  dust,  in  order  that 
the  steam  may  be  able  without  much  hindrance  to  make 
its  escape  from  the  metier. 

The  kindling  is  done  in  the  following  manner : — the 


HAND-BOOK   FOR   CHARCOAL   BURNERS.  103 

drum  or  chimney,  which  has  been  closed  with  small  wood 
three  feet  from  the  top,  is  filled  in  the  upper  part  with 
charcoal,  which  is  ignited.  When  this  mass  of  charcoal 
gets  to  a  glowing  heat,  the  small  wood  under  it  is  consumed, 
and  the  whole  falls  to  the  bottom  of  the  chimney ;  after 
which  the  whole  chimney  is  filled  with  charcoal,  and  when 
we  are  sure  that  the  tire  cannot  be  smothered,  the  cap  is  put 
on  it.  In  this  manner  the  fire  takes  hold  both  above  in 
the  covering  and  below  near  the  hearth  at  the  same  time, 
but  soon  burns  together.  When  settling  is  noticed,  we  must 
fill  in  more  charcoal.  During  the  first  24  hours  this  is 
done  about  every  sixth  hour,  but  afterwards  twice  a  day. 
For  these  fillings  wood  is  never  used,  only  charcoal.  We 
pay  some  attention,  however,  to  its  better  or  poorer  quality, 
and  for  the  last  fillings  we  use  scarcely  anything  but  char- 
coal dust. 

During  the  beginning  of  coaling,  the  dust  above  the 
meiler  must  be  kept  very  loose,  and  be  raked  into  frequent- 
ly, so  that  the  steam  may  easily  escape  through  it.  If  this 
is  not  done  the  meiler  may  begin  to  explode  violently.  In 
some  places  it  is  customary,  during  the  most  dangerous 
period  of  sweating,  for  the  purpose  of  avoiding  explosions, 
to  rake  away  most  of  the  dust  on  a  strip  two  feet  wide 
around  the  covering,  leaving  the  dust  only  three  inches 
thick.  When  the  covering  has  been  coaled,  and  smoke- 
vents  have  been  made,  the  danger  of  explosion  is  passed, 
and  then  the  dust  is  kept  just  as  thick  and  solid  on  the 
covering  as  on  the  sides. 

The  remaining  care  of  the  meiler  is  like  that  of  the 


104:  HAND-BOOK    FOR    CHARCOAL    BURNERS. 


Swedish  standing  meiler  described  above.  Smoke-vents 
are  made  and  moved  as  the  coaling  progresses,  but  canals 
are  not  generally  opened,  before  the  coaling  has  reached 
the  lower  tier  of  billets,  about  three  weeks  after  kindling 
the  meiler. 

The  advantages  of  this  method  of  coaling  are  that  the 
draught  along  the  hearth  can  be  regulated  easier  and  with 
more  certainty,  that  scarcely  any  brands  are  produced  ex- 
cepting from  the  hearth  bridge,  and  that  we  do  not  need 
brushwood  or  any  corresponding  material  for  thatching, 
the  supply  of  which,  in  places  where  extensive  coaling 
is  constantly  carried  on,  at  last  becomes  very  expensive. 

These  meiler s  being  generally  made  very  large,  so  that 
they  contain  as  much  as  9,000  to  10,000  cubic  feet  solid 
wood,  the  consumption  of  charcoal  which  takes  place  in 
filling  seems  not  to  be  out  of  proportion,  and  the  expense  of 
labor  and  watching  ought  to  be  less  than  with  the  common 
standing  meilers,  especially  if  the  work  is  so  arranged  that 
several  meiler  s  are  coaled  at  the  same  time.  The  time  of 
coaling  an  Italian  standing  meiler  is  from  five  to  seven 
weeks. 

4.  THE  COALING  OF  SLABS  AND  OTHER  REFUSE  FROM 
SAWING. 

In  sawing  logs  into  boards,  planks,  and  scantling  we  get 
from  each  log  two  or  four  so-called  slabs,  thin  boards  with 
only  one  side  sawed,  the  other  round  side  consisting  of  the 
exterior  bark  of  the  log.  These  slabs  are  always  like  every 
log  thicker  and  broader  at  one  end.  Their  length  varies 


HAND-BOOK   FOR   CHARCOAL   BURNERS.  105 

very  much,  being  from  12  to  14  and  20  feet  or  more.  At 
many  saw-mills  these  slabs,  as  well  as  the  pieces  sawed  off 
the  sides  of  the  boards,  are  to  a  great  extent  coaled.  This 
is  usually  done  in  standing  meilers  with  a  horizontal  hearth, 
more  or  less  like  the  Swedish  meiler  described  above. 
They  may  of  course  be  put  up  in  various  ways,  and  among 
others  in  the  following  manner  : — When  the  chimney  has 
been  made  by  erecting  three  large  slabs,  we  put  around 
its  lower  end  as  much  brands,  small  charcoal,  and  other 
suitable  materials  as  are  required  for  kindling.  Around 
and  over  this  fuel  we  put  in  a  conic-shaped  heap  some 
larger  refuse  of  sawing,  consisting  chiefly  of  the  ends  of 
logs,  mixed  here  and  there  with  lighter  and  more  combus- 
tible fuel.  Around  this  heap,  thus  forming  the  hearth  of 
the  meiler,  we  raise  the  slabs  edgewise,  with  the  heavy  ends 
down.  Separate  covering  is  not  used.  By  this  method  of 
raising  the  meiler  it  does  not  become  too  steep,  and  becomes 
as  tight  as  is  required.  Kindling  is  easily  done,  and  the 
coaling  spreads  evenly  and  rapidly.  The  rows  of  blocks 
may  be  made  in  this  way : — Take  slabs  of  the  required 
length,  cut  deep' notches  into  them,  place  them  up  around 
and  resting  against  the  meiler  ;  then  lay  into. these  inden- 
tations side-blocks  furnished  with  corresponding  projec- 
tions. 

For  exterior  covering  we  use  both  charcoal  dust  and  saw- 
dust. 

The  rules  given  for  common  wood   apply  also  to  the 
raising,  thatching,  coaling,  sealing,  etc.,  of  this  meiler. 
5* 


106  HAND-BOOK  FOR  CHARCOAL  BURNERS. 

5.  THE  COALING  OF  STUMPS,  ROOTS,  AND  BRANCHES. 

The  stumps  and  roots  of  the  felled  trees  are  chiefly  used 
for  making  tar,  for  which  purpose  they  are  especially  adapt- 
ed ;  still  we  cannot  everywhere  make  tar,  and  the  more  the 
value  of  the  timber  increases,  of  the  greater  importance 
is  it  that  even  these  valuable  parts  of  the  tree  should  be 
more  generally  utilized  than  they  are  ;  among  other  things 
for  making  charcoal.  Experience  has  shown  that  they 
produce  quite  as  good  and  even  better  charcoal  than  the 
stems,  although  the  coaling  requires  more  skill  and  care. 

Of  all  methods  of  coaling  the  German  is  best  adapted 
for  this  purpose,  although  we  do  not  need  any  kindling 
drum  in  the  centre,  which  only  with  great  difficulty  could 
be  made  properly  tight  with  such  material  as  that  of  which 
we  here  speak.  After  removing  the  stumps  and  roots  from 
the  ground,  the  former  are  split  if  they  have  any  consider- 
able thickness.  With  an  axe  and  saw  we  try  to  make  all  the 
stumps  and  roots  to  be  used  as  straight  and  free  from 
knots  as  possible.  The  earth  and  stone  among  the  roots 
should  be  cleaned  out  carefully.  If  all  this  is  done  early 
in  the  spring,  the  wood  will  have  a  chance  to  dry  sufficient- 
ly before  coaling  in  the  fall. 

The  raising  requires  much  practice,  and  must  be  done 
with  exactness.  We  must  especially  see  that  the  meiler  is 
uniformly  tight  on  all  sides,  for  otherwise  it  invariably 
happens  that  consumption  takes  place  on  the  side  where 
the  wood  is  most  open.  Around  the  place  of  kindling  we 
put  small  and  dry  wood,  but  over  this,  and  generally  nearest 


HAND-BOOK    FOR    CHARCOAL    BURNERS.  107 

the  centre,  we  put  the  largest  stumps,  observing  that  their 
smaller  ends  should  be  as  a  rule  turned  to  the  ground,  and 
that,  if  for  the  sake  of  tightness  or  for  any  other  reason  the 
butt-end  is  turned  down,  it  should  be  placed  on  a  little  stone 
or  block,  in  order  that  it  may  be  more  thoroughly  coaled. 
All  openings  should  be  filled  as  well  as  possible  with  roots, 
twigs,  etc.  For  the  outside  layer  of  the  meiler  we  use 
some  small,  more  easily  coaled  material— if  need  be,  small 
split  stem  wood. 

For  the  inside  layer  of  covering,  moss  is  better  than 
brushwood.  In  managing  the  meiler  during  the  coaling 
process  we  observe  the  rules  already  given,  taking  this 
fact  into  consideration,  that  the  coaling  should  progress 
more  slowly,  or  the  larger  stumps  will  not  be  thoroughly 
coaled.  In  removing  the  meiler  we  should  be  very  careful 
to  extinguish  the  fire  thoroughly,  and  not  put  the  charcoal 
under  the  shed  too  soon,  for  the  stumps  frequently  contain 
cavities,  and  in  these  the  fire  may  continue  to  burn  unseen 
for  a  long  time.  Meilers  may  be  made  of  branches  and 
twigs  only,  and  it  has  been  found  that  the  Italian  method 
of  coaling  on  a  bridge  is  best  for  this  purpose.  (Such  a 
bridge  on  the  hearth  is  also  serviceable  for  stumps  and 
roots,  which  may  then  be  raised  with  the  butt-end  down.) 
The  billets  should  as  a  rule  be  cut  somewhat  shorter  than 
usual,  but  any  certain  length  cannot  be  fixed,  for  the 
branches  must  be  cut  off  at  all  crooks  and  joints,  in  order 
to  obtain  the  proper  tightness  of  the  meiler.  The  billets 
being  smaller,  the  meiler  should  also  be  made  smaller,  and 
be  coa'ed  much  more  rapidly  than  when  common  billets 


108  HAND-BOOK   FOR    CHARCOAL    BURNERS. 

are  used.  Two-thirds  of  the  time  used  for  coaling  a  meiler 
of  the  same  size,  made  from  ordinary  billets,  is  regarded 
as  sufficient. 

6.  STANDING   MEILER   ON    A  HORIZONTAL    HEARTH   WITH 
A  CENTRE-BLOCK. 


FIG.  6. 

The  Making  and  Watching  of  the  Meiler. 

The  different  kinds  of  meilers  which  have  now  been 
treated  have  in  common  that  the  kindling  is  done  more 
or  less  exclusively  in  the  centre  of  the  rneiier  near  the 
hearth,  and  the  coaling  gradually  spreads  from  this  cen- 
tral point  outward,  and  even  more  rapidly  upward.  Next 
in  order  will  be  to  describe  a  standing  meiler,  likewise  on 
a  horizontal  hearth,  but  which  is  kindled  from  above.  It 
is  built  in  the  following  mariner : — In  the  centre  of  the 
hearth  is  erected  perpendicularly  a  straight  block  7  or  8 
inches  thick,  firmly  supported  by  sloping  billets.  This  is 
called  the  centre-block,  and  is  about  3  feet  shorter  than 
the  meiler  billets,  which  are  about  10  feet  long;  by  put- 


HAND-BOOK    FOR    CHARCOAL    BURNERS.  109 

ting  in  this  centre-block,  there  is  formed  above  it  a  chim- 
ney or  drum  of  corresponding  depth.  Beside  or  on  this 
block  the  guide-pole  is  placed,  after  which  we  raise  the 
billets  of  straight  and  small  wood  as  close  together  as  pos- 
sible. The  larger  wood  is  placed  3  or  4  feet  from  the 
centre,  and  afterwards  the  raising  progresses  according  to 
rules  given  heretofore.  When  the  meiler  has  obtained  the 
proper  circumference  the  projecting  ends  are  cut  off,  and 
hollow  places  which  may  be  found  are  filled  carefully 
with  short  and  small  wood,  of  which  we,  however,  only 
lay  so  much  on  the  inner  billets  that  the  meiler  may  be 
moderately  and  uniformly  rounded  on  all  sides.  Any 
actual  covering  is  not  used.  Thatching  with  brushwood 
and  dust  is  done  in  the  usual  manner.  Kindling  the  mei- 
ler is  done  in  the  3  feet  deep  drum  over  the  centre-block. 
Charcoal  is  preferable  for  this  purpose.  After  about  half 
an  hour,  when  the  fire  has  got  well  started,  both  in  the 
charcoal  and  in  the  surrounding  billets,  the  drum  is  filled 
to  the  brim  with  charcoal  and  small  dry  wood,  and  is 
afterwards  covered  with  a  somewhat  projecting  turf  of 
sod,  upon  which  is  put  charcoal  dust.  Simultaneously 
with  the  kindling  we  open  4  to  5  canals,  which  are  closed 
again  as  soon  as  the  cap  is  put  on  the  chimney,  and  the 
meiler  has  become  sufficiently  heated. 

Now  we  open  around  on  the  covering,  2  to  3  feet  from 
the  brow,  small  air-vents,  which  afterwards  during  the 
first  days  are  not  perfectly  closed,  but  are  placed  and  regu- 
lated in  such  a  way  as  to  produce  a  uniform  spreading  of 
the  heat  and  coaling  from  the  drum  in  every  direction. 


110  HAND-BOOK    FOR    CHARCOAL    BURNERS. 

The  dust  on  the  meiler  should  be  kept  so  loose  that  the 
volatile  products  of  coaling  may  escape. 

As  soon  as  the  sod  over  the  chimney  settles  it  is  taken 
off,  and  more  charcoal  and  small  wood  is  iilled  in.  At 
each  filling  we  examine  carefully  with  the  filling-rod 
whether  any  consumption  has  taken  place  on  the  sides  of 
the  chimney.  If  so,  the  vacuum  produced  should  be  iilled 
with  wood,  and  the  covering  about  it  should  be  tightened, 
by  putting  on  more  dust  which  is  well  packed.  The  more 
seldom  these  fillings  are  needed,  and  the  farther  down  the 
coaling  extends  during  the  first  days,  spreading  uniformly 
on  every  side,  the  better  for  the  meiler.  After  the  first 
four  days,  we  need  not  fill  oftener  than  once  each  or  every 
other  day,  and  on  the  seventh  or  eighth  the  filling  entirely 
ceases.  The  whole  upper  part  of  the  meiler  is  then  gener- 
ally coaled  and  packed  down,  and  smoke-vents  are  made 
at  a  suitable  distance  below  the  brow ;  after  which  the 
coaling  should  be  so  regulated  by  suitable  canals  and 
smoke-vents,  and  by  observing  rules  given  heretofore,  that 
the  fire  comes  out  simultaneously  on  all  sides  at  the  foot 
of  the  meiler. 

The  Advantages  and  Disadvantages  of  this  Method. 

The  method  of  kindling  a  standing  meiler  at  the  top,  and 
from  there  conducting  the  whole  coaling  process  outward 
and  downward,  has  this  incontestable  advantage,  that  the 
coaling  already  from  the  beginning  progresses  in  a  direc- 
tion which  is  more  or  lets  opposite  that  of  the  draught. 
By  this  we  also  explain,  that  the  fillings  are  of  far  less  im- 


HAND-BOOK   FOR   CHARCOAL    BURNERS.  Ill 

portance  than  when  the  meiler  is  kindled  at  the  hearth. 
But  this  advantage  is  counterbalanced  by  several  disadvan- 
tages, which,  however,  seem  to  depend  more  upon  im- 
proper arrangements,  and  should  not  be  ascribed  to  the 
method  of  kindling,  which  undoubtedly,  so  far  as  it  is 
concerned,  is  correct. 

The  principal  disadvantage  is,  that  the  coaling  has  a 
tendency  to  progress  more  or  less  along  the  sides  of  the 
meiler,  so  that  a  lot  of  brands  and  half -charred  billets  re- 
mains in  the  centre  of  the  meiler,  especially  nearest  the 
hearth,  and,  like  the  lower  ends  of  the  billets,  keeps  cold 
and  damp.  In  the  next  place,  it  is  quite  difficult  to  con- 
duct the  coaling  properly,  even  in  the  upper  part  of  the 
meiler,  outward  from  the  drum,  toward  the  brow.  The 
billets  being  so  long,  it  is  difficult  for  them  to  settle  in  the 
course  of  coaling,  and  the  meiler  becomes  open.  Finally, 
it  has  been  remarked  concerning  these  meilers,  that  they 
have  a  great  tendency  to  explode.  All  these  things  put 
together  have  caused  this  method,  although  founded  on 
correct  principles,  to  be  but  little  developed  and  adopted 
far  less  than  it  probably  deserves. 

In  regard  to  the  difficulty,  or  rather  the  impossibility  of 
conducting  the  coaling  in  the  centre  of  the  meiler  down 
to  the  hearth,  or  getting  it  heated  at  the  foot,  we  know 
that  this  depends,  at  least  to  a  great  extent,  on  mismanage- 
ment. Putting  a  large  centre-block,  difficult  to  coal,  just 
in  the  middle  where  we  want  the  coaling  to  progress,  is 
a  mismanagement  of  this  kind  ;  and  if  we  put  small,  dry 
wood  or  brands  in  place  of  this  centre-block,  which  could 


112  HAND-BOOK   FOR   CHARCOAL    BURNERS. 

undoubtedly  he  very  easily  done,  then  a  quite  important 
difficulty  would  thereby  be  removed.  In  the  next  place 
it  is  evident  that,  if  we  wish  to  force  the  fire  and  coaling 
downward,  we  ought  to  make  it  possible  for  the  air  to 
enter  from  below.  But,  on  the  contrary,  the  few  canals, 
that  were  opened  during  the  kindling  process,  are  very 
hastily  closed,  and  air-holes  are  opened  in  the  covering 
instead.  This  is  clearly  entirely  wrong,  and  we  may  be 
inclined  to  admit  the  truth  of  the  assertion,  made  by  many 
colliers,  that  the  meiler  hearth  should  not  be  too  tight, 
since  in  that  case  it  is  apt  to  keep  too  cold,  and  the  coal- 
ing process  will  produce  a  large  number  of  brands.  If  it 
is  then  decidedly  wrong,  wrhen  the  collier  desires  the  coal- 
ing to  progress  downward,  not  to  use  the  only  sure  remedy 
at  his  command,  namely,  to  open  canals  at  the  foot  of  the 
meiler,  still  it  does  not  follow  that  a  few  canals  opened 
in  the  usual  way  are  sufficient.  On  the  contrary,  the  na- 
ture of  the  case  requires  that  even  the  air  admitted  from 
below  should  especially  make  its  way  directly  up  through 
the  billets  to  the  fire  in  the  upper  part  of  the  meiler. 
These  canals  will  certainly  be  of  considerable  advantage, 
still  they  will  not  perfectly  accomplish  the  object  desired 
If  we,  on  the  other  hand,  could  produce  draught  at  the 
foot  of  the  meiler,  in  such  a  manner  that  the  air  must 
proceed  from  there  along  the  hearth  to  the  centre  of  the 
meiler,  and  from  there  take  its  way  up  through  the  wood, 
then  it  would  clearly  be  in  our  power  to  force  the  coaling 
process  down  to  the  hearth.  But  this  ought,  indeed,  to  be 
easily  accomplished  by  conducting  the  air  from  the  foot 


HAND-BOOK   FOR    CHARCOAL    BURNERS.  113 

of  the  meiler,  by  making,  before  raising  the  billets,  a  few 
canals  which  extend  t  >  the  centre  of  the  meiler,  of  which 
more  hereafter.  In  the  next  place,  in  regard  to  the  diffi- 
culty of  properly  conducting  the  coaling  process  in  the 
upper  part  of  the  meiler,  from  the  place  of  kindling  to 
the  brow,  it  should  be  first  of  all  remarked  that  it  must 
always  be  more  difficult  to  conduct  the  coaling  crosswise, 
through  billets  of  different  thickness  standing  side  by 
side,  than  lengthwise,  through  small  wood.  Again,  when 
we  put  the  place  of  kindling  at  the  top  for  the  very 
purpose  of  conducting  the  coaling  process  from  above 
downward,  it  is  in  direct  opposition  to  this  purpose  to 
give  the  upper  part  of  the  meiler  an  almost  flat  form,  for 
coaling  which,  it  is  necessary  to  conduct  the  heat  horizon- 
tally outwards  at  the  same  time,  that  we  want  it  to  pro- 
gress downward  perpendicularly.  Undoubtedly,  the  cov- 
ering of  a  meiler  of  this  kind  should,  on  the  contrary,  be 
made  as  steep  as  the  work  of  filling  the  chimney,  turning 
the  dust,  etc.,  will  permit. 

The  third  disadvantage  mentioned,  that  the  great  length 
of  the  billets  prevents  the  meiler  from  settling  as  the  coal- 
ing progresses,  vanishes,  if  in  making  the  covering  the 
wood  underneath  is  not  made  longer  than  that  which  is 
used  in  the  common  standing  meiler.  Perhaps  this  disad- 
vantage depends  still  more  upon  the  difficulty  of  getting 
the  coaling  to  progress  downwards  toward  the  hearth.  If 
we  remove  this  difficulty  and  get  rid  of  the  centre-block 
the  settling  will  undoubtedly  take  place  without  any  seri- 
ous obstacles. 


114:  HAND-BOOK   FOR   CHARCOAL    BURNERS. 

Finally,  it  is  claimed  that  this  kind  of  meiler  is  very 
liable  to  explode  violently ;  this  is  without  doubt  closely 
connected  with  the  difficulty  of  being  able  to  conduct  the 
coaling  properly  outward  from  the  place  of  kindling  ;  and 
the  holes  made  above  the  brow,  which,  though  they  serve 
as  air-holes  and  smoke-vents,  certainly  help  to  form  explo- 
sive gases.  Without  entering  upon  a  more  thorough  ex- 
planation of  this,  it  seems  perfectly  clear  that  a  standing 
meiler  with  steep  coverings,  kindled  from  above,  and  in 
which  the  coaling  process  constantly  progresses  in  the  same 
main  direction,  from  above  downward,  if  too  much  air  is 
not  admitted  will  sweat  slower  and  less  violently  than  a 
meiler  kindled  at  the  hearth ;  and  that  consequently  the 
former,  if  the  dust  on  the  covering  is  kept  properly  loose 
by  turning,  will  not  explode  more,  but  on  the  contrary  less, 
than  the  latter.  It  should  also  be  observed  that  if  the  air 
is  permitted  to  enter  at  the  foot,  and  holes  made  above  the 
brow  be  made  to  serve  only  as  smoke-vents,  which,  the 
meiler  being  kindled  at  the  top,  should  always  be  opened 
soon,  it  is  difficult  to  suppose  that  there  will  be  formed 
any  considerable  amount  of  explosive  gas. 

Suggestion   as  to  Kindling  a  Standing  Meiler   on    a 
Horizontal  Hearth,  in  the  Covering. 

A  standing  meiler  on  a  horizontal  hearth  to  be  kindled 
at  the  top  might  indeed  be  more  conveniently  built  and 
managed  in  about  the  following  manner: — In  the  place  of 
a  centre-block  we  put  together  some  small  and  dry  wood 
about  3  feet  shorter  than  the  other  meiler  billets.  This 


HAND-BOOK   FOR   CHARCOAL   BURNERS.  115 

small  wood  we  bind  together  in  two  places  with  willows 
or  wire,  into  a  bundle  about  one  foot  in  diameter.  This 
bundle  is  raised  perpendicularly  in  the  centre  of  the  hearth 
and  well  supported.  On  the  hearth  we  lay  in  the  direc- 
tion of  the  radius  and  at  equal  distances  from  each  other 
i  to  6  air-drums,  so  long  that  one  end  extends  a  few 
inches  beyond  the  periphery  of  the  meiler  after  it  has  been 
covered  with  dust,  and  the  other  en(^  is  situated  about  2 
feet  from  the  centre  of  the  meiler ;  then  we  lay  4  to  6 
more  similar  air-drums,  with  one  end  5  to  6  feet  from  the 
centre. 

These  drums  or  canals,  a  few  inches  high,  can  easily  be 
obtained  by  two  boards  or  slabs  pinned  together  so  as  to 
form  a  right-angled  triangle  while  resting  on  the  ground 
with  the  open  side  ;  they  can  of  course  be  made  in  other 
ways.  The  main  thing  is  that  they  should  be  made  of  dry 
wood,  which  will  coal  simultaneously  with  the  billets,  and 
that  they  are  tight  along  their  whole  length  between  the 
two  open  ends.  This  tightening  may,  if  necessary,  be  ob- 
tained by  putting  on  and  packing  some  earth  or  dust.  The 
billets  being  made  the  usual  length  are  raised  in  one  or 
two  tiers  around  the  bundle  described  above,  which  should 
be  immediately  surrounded  with  dry  billets  of  a  smaller 
size.  After  the  billets  are  raised  we  put  on  a  high  cover- 
ing as  steep  as  the  management  of  the  meiler  will  permit, 
say  with  a  slope  of  30  to  35  degrees.  At  the  top  the  cov- 
ering should  be  flat,  so  as  to  form  a  circular  plane  about 
four  feet  in  diameter,  upon  which  the  meiler  is  kindled  in 
a  small  heap  of  dry  fuel  (charcoal  is  preferable),  which 


116  HAND-BOOK   FOR   CHARCOAL   BURNERS. 

also  extends  down  into  the  chimney  formed  by  the  billets 
surrounding  the  bundle  of  small  wood. 

Covering  with  brushwood  and  dust  is  done  in  the  usual 
way. 

If,  after  kindling,  a  few  smoke-vents  are  opened  in  the 
covering  near  around  the  place  of  kindling,  and  air  is  ad- 
mitted through  the  longer  air-drums  on  the  hearth,  but  the 
rest  of  the  meiler  k^pt  tight,  then  the  coaling  will  progress 
downwards  cylindrically.  If  the  smoke-vents  are  gradu- 
ally moved  outwards,  then  the  coaling  process  will  gradu- 
ally take  the  same  direction.  By  properly  managing  and 
regulating  the  admittance  of  air  through  the  air-drums, 
and  by  properly  regulating  the  smoke- vents,  and  making 
these  of  the  right  size,  or  loosening  the  thin  dust  covering 
above  the  brow,  we  have  it  in  our  power  to  make  the  coal- 
ing process  from  the  very  beginning  spread  so  as  to  assume 
the  form  of  an  inverted  cone  ;  thus  the  coaling  process 
will  reach  the  hearth  sooner  than  it  reaches  the  brow  ;  in 
other  words,  when  the  covering  has  been  coaled,  the  coal- 
ing process  must  have  progressed  about  in  the  manner  ex- 
hibited in  Fig.  3. 

When  the  coaling  process  gradually  extends  towards  the 
periphery  near  the  hearth,  then  the  air-drums  will  of 
course  be  coaled,  and  the  draught  thus  keeps  even  space 
with  the  coaling  process  from  the  centre  to  the  periphery. 

We  may  also,  if  it  is  found  desirable,  close  the  longer 
air-drums,  and  in  their  stead  open  the  shorter  ones.  As 
a  matter  of  course,  we  may  make  the  draught  in  each  of 
these  pipes  as  light  as  we  please. 


HAND-BOOK   FOE   CHAECOAL   BURNERS.  117 

When  the  meiler  has  been  kindled  in  the  heap  of  fuel 
piled  up  above  the  steep  covering,  which  fuel  is  covered 
in  the  usual  way,  after  kindling,  with  sod  and  dust,  it 
would  seem  that  no  farther  fillings  are  required.  When 
the  coaling  process  progresses  downward  in  the  centre,  the 
upper  part  of  the  covering  to  be  sure  settles  correspond- 
ingly, so  that  a  depression  is  formed  surrounded  by  a  pro- 
jecting circular  edge  ;  but  this  does  no  harm. 

Where  the  meiler  has  settled,  it  should  of  course  be 
packed  down,  in  order  that  the  charcoal  may  be  protected 
from  the  gases  which  are  formed  in  the  meiler,  and  which 
are  destructive  to  charcoal.  The  coaling  process  gradually 
progresses  outward,  the  depression  above  referred  to 
gradually  widens,  and  when  the  coaling  process  has  reach- 
ed the  brow,  it  disappears  entirely,  after  which  every 
thing  goes  on  in  the  same  way  as  in  a  meiler  with  a 
chimney. 

A  meiler  made  and  managed  in  this  way  ought  to  be 
exempt  from  the  difficulties  mentioned  above  in  regard  to 
coaling  with  a  centre-block,  while  it  ought  to  retain  in  an 
increased  degree  the  advantages  which  the  method  of 
kindling  the  meiler  at  the  top  certainly  offers.  It  is,  how- 
ever, quite  probable  that  the  method  there  recommended, 
when  carried  into  practice,  might  need  some  modifi- 
cation. 

Finally,  it  should  be  observed  that  when  coaling  is  done 
in  winter,  it  might  be  most  advisable  to  have  a  chimney, 
and  kindle  in  the  usual  manner  at  the  hearth  ;  for  other- 
wise it  may  easily  happen,  that  the  lower  ends  of  the  bil- 


118  HAND-BOOK   FOR   CHARCOAL    BURNERS. 

lets  freeze  together  and  to  the  hearth  before  the  fire  gets 
down  there. 

7.  STANDING  MEILERS  ON  SLOPING  HEARTHS. 

Introduction. 

While  the  different  kinds  of  metiers,  described  above, 
have  this  in  common,  that  they  are  built  on  horizontal 
hearths,  and  that  it  is  in  regard  to  them  all  a  principal 
rule  that  the  billets  should  be  arranged  symmetrically 
around  the  central  axis  of  the  metier,  and  that  the  coaling 
process  should  spread  as  uniformly  as  possible  to  all  sides, 
we  also  have  standing  metiers  built  on  sloping  hearths,  on 
which  neither  the  raising  nor  especially  the  coaling  of  the 
meiler  can  be  done  symmetrically  around  its  centre  line ; 
but  they  have  this  advantage,  that  they  can  without  much 
difficulty  be  built  on  the  slope  of  a  hill,  or  we  may  say  in 
any  place  where  the  ground  is  capable  of  being  worked 
and  where  a  supply  of  water  is  at  hand,  while  they  do  not 
require  that  the  hearth  shall  be,  or  be  made  horizontal. 
The  hearth,  which  is  prepared  in  the  usual  way,  should 
for  these  metiers  always  slope  somewhat,  and  the  extent  of 
this  sloping  must  not  exceed  about  two  feet  between  the 
highest  and  lowest  points  of  the  periphery  of  the  metier. 
The  hearth  should  also  be  smooth,  without  depression  or 
elevation.  Still  some  colliers  make  it  somewhat  convex  at 
the  centre.  The  metier  is  made  of  unsplit  billets  from  9J 
to  10  feet  long,  without  any  separate  covering-wood. 

We  distinguish  between  two  materially  different  kinds 


HAND-BOOK   FOR   CHARCOAL   BURNERS.  119 

of  standing  metiers  on  a  horizontal  hearth,  namely,  the 
Vermland  metier,  which,  as  the  name  indicates,  is  especi- 
ally used  in  Vermland,  and  also  in  the  adjoining  parts  of 
Dalarne  and  Orebro,  and  the  Molinder  metier,  named 
after  its  inventor,  which  in  respect  to  its  management  is 
more  like  the  standing  metiers  already  described,  and 
should  therefore,  although  recently  adopted  in  practice,  be 
described  first.  It  should,  however,  be  stated  that  in  the 
parish  Kroppa  in  Vermland  there  has  from  time  imme- 
morial been  a  similar  method  of  coaling,  which  has  now 
gone  out  of  use. 

The  Molinder  Metier. 

The  building  of  the  metier  begins  with  erecting  in  the 
centre  of  the  hearth  a  guide- pole  about  six  inches  thick  at 
the  butt-end,  and  at  least  four  feet  longer  than  the  billets; 
this  guide-pole  should  stand  firmly.  Immediately  around 
this  pole  is  raised  shorter  billets,  in  order  that  the  metier 
may  not  become  too  steep,  and  then  billets  of  full  length, 
observing  that  the  smallest,  driest,  and  most  easily  ignited 
billets  are  raised  a  breadth  of  about  three  feet  directly  out 
from  the  centre  toward  that  side  where  the  hearth  is  the 
highest.  Around  this  so-called  fireplace  is  raised  only 
billets  of  medium  size.  The  size  of  the  billets  is  increased 
as  we  go  down  the  slope  until  we  reach  the  lowest  part  of 
the  hearth,  where  the  largest  billets  are  used.  The  exte- 
rior layer  of  the  metier  should,  however,  consist  exclusively 
of  small  billets.  In  raising  the  billets,  it  should  also  be 
observed,  that  while  the  billets  on  the  upper  and  lower 


120  HAND-BOOK    FOE   CHARCOAL    BURNERS. 

sides  of  the  meiler  are  put  perpendicularly  against  the 
guide-pole,  they  should,  on  the  remaining  sides,  slope 
somewhat  toward  the  upper  side  of  the  meiler.  The  slop- 
ing should  correspond  with  the  sloping  of  the  hearth,  and 
the  purpose  is  to  give  the  meiler  a  more  steady  position. 
Where  we  want  to  put  canals,  these  may  be  made  more 
serviceable  in  the  manner  explained  heretofore,  by  laying, 
before  we  raise  the  billets,  poles  upon  the  hearth  from  the 
centre  to  the  periphery,  which  are  drawn  out  as  the  rais- 
ing of  the  billets  progresses,  or  by  making  small  air-drums. 
After  the  raising  of  the  billets  is  done,  the  covering,  as 
the  upper  part  is  called,  is  smoothed  and  tightened  with 
twigs  and  other  small  wood.  Immediately  in  front  of  the 
fireplace  we  put  up,  two  feet  from  each  other,  two  wooden 
blocks  two  feet  high  and  six  inches  thick,  upon  which  is 
laid  a  third  block  of  the  same  size.  Under  this  roof, 
which  prevents  the  dust  from  falling  down,  the  meiler  is 
kindled,  which  is  done  easier  if  we,  nearest  to  the  place 
of  kindling,  put  up  two  feet  deep  into  the  fireplace  com- 
mon dry  stove  wood,  and  upon  this,  meiler  billets  of  cor- 
responding less  length  than  that  of  the  other  billets.  The 
kindling  of  the  meiler  is  done  by  building  a  little  fire, 
which  soon  gets  into  the  fireplace,  by  opening  a  canal  op- 
posite it  on  the  lower  side  of  the  meiler.  This  canal  is 
afterwards  generally  kept  open  through  the  whole  coaling 
process.  When  the  fire  has  got  started  sufficiently  the 
kindling  place  is  closed  with  brushwood  and  dust,  but 
not  too  tight  in  the  beginning.  The  intention  now  is  that 
the  coaling  process  shall  proceed  immediately  into  the 


HAND-BOOK   FOR   CHARCOAL    BURNERS.  121 

fireplace,  which  is  facilitated  by  the  natural  tendency  of 
the  fire  to  go  down  the  slope  directly  against  the  draught 
from  below.  In  the  next  place,  if  the  wood  in  the  fire- 
place is  quite  dry  and  the  hearth  very  sloping,  or  if  it 
blows  hard  from  the  valley  side,  the  canals  may  have  to 
be  closed  for  a  while. 

But  while  the  coaling  thus  progresses  out  along  the  fire- 
place, it  should  also  spread  gradually  on  the  different  sides 
of  it,  which  is  secured  by  loosening  the  dust  near  the  foot 
of  the  meiler  on  both  sides  of  the  kindling  place.  On 
the  other  hand,  it  is  well  tightened  with  dust,  for  other- 
wise the  coaling  will  not  follow  the  hearth. 

By  regulating  the  draught  from  the  lower  part  of  the 
meiler,  and  by  keeping  the  dust  properly  loose  on  the  up- 
per side,  we  are  now  able  to  manage  the  spreading  of  the 
coaling  process,  so  that  it  assumes  the  form  of  a  fan  grad- 
ually opened  more  and  more,  so  that  when  the  edge  of  the 
coaling  process  has  got  out  along  the  fireplace  to  the 
centre  of  the  meiler,  its  upper  half  has  mostly  been  coaled. 
If  the  coaling  process  progress  so  rapidly  in  the  fireplace, 
that  its  spreading  thence  to  the  sides  can  not  properly  keep 
pace,  then  steep  offsets  will  be  formed.  The  meiler  is 
split,  as  it  were,  into  two  parts.  Fillings  may  then  be- 
come necessary  even  until  the  fire  goes  out  at  the  lower 
side  of  the  meiler,  and  loss  of  charcoal,  together  with  the 
production  of  a  large  number  of  brands,  cannot  be  avoided. 
But  if  the  billets  are  tolerably  dry  and  raised  with  care, 
and  the  hearth  is  in  proper  condition,  this  should  not 
happen,  provided  the  collier  attends  to  his  work.  It  may 


122  HAND-BOOK   FOR   CHARCOAL    BURNERS. 

also  happen,  especially  if  the  billets  are  sour,  or  if  the 
hearth  has  but  a  moderate  slope,  that  the  coaling  out 
along  the  fireplace  progresses  too  slowly ;  this  is  remedied 
by  opening  one  or  two  new  canals  about  two  feet  distant 
from  the  one  opened  before.  When  the  coaling  has 
reached  the  centre,  which  is  indicated  by  the  meiler  set- 
tling in  that  place,  more  canals  are  gradually  opened,  so 
that  finally  the  whole  uncoaled  part  of  the  meiler  will  be 
furnished  with  canals.  Wherever  the  coaling  has  reached 
the  foot  of  the  meiler,  the  brands  are  taken  out  in  this 
place,  after  which  the  coaled  part  is  packed  down  in  the 
best  manner  possible  as  a  protection  against  draught; 
while  on  the  other  hand  the  dust  is  loosened  with  a  rake 
in  front  of  the  part  where  the  coaling  is  progressing  ;  and 
thus  we  continue,  until  the  fire  gradually  comes  out  every- 
where at  the  foot,  when  the  coaling  is  finished.  In  this 
method  of  coaling,  which,  however,  certainly  requires  per- 
fectly dry  billets,  the  coaling  process  progresses  from  be- 
ginning to  end,  as  it  were  of  its  own  accord,  in  a  direc- 
tion opposite  that  of  the  draught ;  whereby  we  can  par- 
tially explain  that  no  fillings  are  required.  The  glowing 
charcoal  already  formed  can  without  difficulty  be  pro- 
tected from  the  gaseous  substances  formed  in  the  meiler. 
Finally,  we  also  have  it  considerably  in  our  power,  if  the 
hearth  is  perfect,  and  no  storms  arise,  to  regulate  and 
moderate  the  coaling  temperature,  so  to  speak,  everywhere 
in  the  meiler.  From  this  it  seems  to  follow  that  the 
charcoal  everywhere,  excepting  at  the  place  of  kindling, 
will  have  a  uniformly  good  quality.  This  method  of  coal- 


HAND-BOOK  FOR  CHARCOAL  BURNERS.         123 

ing  is,  however,  still  so  new,  and  upon  the  whole  so  little 
used,  that  we  have  no  reliable  information  in  regard  to  its 
advantages  and  disadvantages. 

The  Vermland  Meiler. 

The  Yermland  meiler  is  built  either  with  a  centre-block 
or  with  a  chimney  extending  down  to  the  hearth.  The 
latter  method  seems  the  best,  but  the  former  is  used  the 
most.  This  meiler  has  its  fireplace,  which  extends  from 
the  centre  to  the  lower  edge  of  the  hearth.  This  fireplace 
is  made  of  only  dry  and  small  wood,  preferring  such  as  has 
no  value  for  other  purposes,  such  as  decayed  and  damaged 
timber;  for  it  is  more  or  less  exposed  to  consumption, 
which,  among  other  things,  is  proved  by  the  fact  that  in 
old  hearths  the  place  beneath  the  fireplace  is  strewn  witli 
ashes  of  a  loose  quality  without  any  cinders.  Nearest  the 
centre  of  the  hearth,  as  also  around  the  fireplace,  medium- 
sized  billets  are  raised,  and  further  out,  especially  on  the 
upper  side  of  the  meiler,  the  largest  billets,  then  medium- 
sized  ones,  and  in  the  exterior  layer  the  smallest  ones.  In 
consequence  of  the  situation  of  the  fireplace  on  the  lower 
side  of  the  meiler,  it  is  now  far  more  important  than  in  the 
Molinder  meiler  that  the  greater  part  of  the  billets,  in  the 
manner  before  described,  should  be  raised  so.as  to  slope 
more  toward  the  upper  side  of  the  meiler  the  more  the 
hearth  slopes.  If  this  is  neglected,  it  may  very  probably 
happen,  when  the  fire  progresses  into  the  fireplace,  that  the 
walls  formed  around  it  tumble  down  or  get  out  of  shape, 
whereby  the  coaling  gets  out  of  order,  so  that  some  of  the 


124:  HAND-BOOK  FOR   CHARCOAL   BURNERS. 

billets  burn  up,  while  others  remain  uncoaled,  etc.  Expe- 
rienced colliers,  therefore,  always  pay  close  attention  to  this 
sloping  position  of  the  billets,  whereby  the  meller,  seen 
from  certain  positions,  looks  as  though  it  were  twisted  into 
a  spiral. 

The  tightening,  thatching,  and  covering  with  dust  is 
done  in  the  same  mariner  as  it  has  been  explained  in  re- 
gard to  the  common  Swedish  standing  meiler  on  a  hori- 
zontal hearth.  The  kindling  is  done  over  the  centre-block 
or  down  in  the  chimney  with  wood,  or  what  is  better  with 
charcoal.  The  kindling  is  assisted  by  opening  7  or  8  ca- 
nals around  the  meiler,  which  are  kept  open  until  it  is 
well  kindled,  and,  if  the  kindling  is  done  over  the  centre- 
block,  until  the  fire  has  reached  the  hearth.  On  account 
of  the  tendency  of  the  fire  to  make  its  way  especially  in 
that  direction  in  which  the  hearth  slopes,  and  on  account 
of  the  more  combustible  quality  of  the  wood  in  the  fire- 
place, the  fire  will  progress,  if  wind  from  some  other 
quarter  does  not  prevent  it,  almost  exclusively  in  the  fire- 
place. To  assist  in  securing  this  result,  a  few  smoke-vents 
are  opened  above  it,  which  are  gradually  moved  outward 
ahead  of  the  coaling  process  ;  and  right  in  front  of  the 
fireplace  is  opened  a  canal,  which  is  usually  kept  open 
until  the  coaling  reaches  the  foot  of  the  meiler. 

Filling-wood  is  put  in  as  often  as  we  see  it  is  needed. 
During  the  first  day  the  settling  confines  itself  to  the 
place  of  kindling,  but  afterwards  it  moves  outward  along 
the  fireplace  and  over  the  brow  down  toward  the  foot  of 
the  meiler ',  where  it  ceases.  In  filling  places  where  the 


HAND-BOOK   FOE   CHARCOAL   BURNERS.  125 

meiler  settles  we  should  be  very  careful  not  to  let  the 
dust  fall  down,  for  thereby  the  draught  will  be  hindered. 
The  time  required  for  the  fire  to  reach  the  foot  of  the 
meiler  may  be  3  to  4  days  or  still  longer.  Some  meilera 
require  fillings  all  the  way  down,  others  require  only  small 
fillings  in  two  or  three  places.  Meilers  having  a  chimney 
of  course  always  require  large  fillings  in  the  centre;  gen- 
erally the  fillings  depend  as  to  their  quantity  and  fre- 
quency for  the  most  part  on  the  quality  of  the  hearth  and 
the  dryness  of  the  billets.  Large  and  green  billets  always 
make  larger  fillings  necessary.  Many  colliers  think  it  is 
injurious  to  fill  many  times  in  the  same  place  in  the  cen- 
tre of  the  meiler,  wherefore  they  also  try  by  making 
large  canals  and  smoke-vents  on  the  lower  side  to  bring 
the  fire  by  force  as  it  were  out  from  the  centre.  This  is, 
however,  wrong,  for  both  the  billets  and  the  hearth  need 
time  to  dry. 

If  the  coaling  process  leaves  the  centre  too  soon  and 
before  it  is  deep  enough,  which  readily  happens  in  meilers 
with  centre-blocks,  we  get  in  the  centre  a  lot  of  brands, 
and  the  process  of  coaling  will  also  in  other  respects  be 
miserable  and  difficult  to  manage.  The  more  the  coaling 
is  done  internally,  before  the  fire  begins  to  proceed  out- 
ward, which  under  ordinary  circumstances  seldom  or 
never  takes  very  long,  the  better  it  is  for  the  coaling  af- 
terwards. On  the  other  hand,  to  set  fire  to  the  cold  wood, 
as  we  say,  generally  produces  a  protracted  consumption 
at  the  walls,  before  the  billets  in  the  interior  part  of 
the  meiler,  whither  the  coaling  is  now  to  be  conduct- 


126  HAND-BOOK    FOR   CHARCOAL    BURNERS. 

ed,  become  sufficiently  heated  and  dried  to  begin  coal- 
ing. 

Some  colliers,  who  are  very  anxious  to  avoid  fillings  and 
to  get  the  fire  down  to  the  lower  foot  of  the  hearth  as  soon 
as  possible,  kindle  in  the  covering  more  or  less  near  the 
brow ;  but  from  what  has  been  said  above,  it  is  not  diffi- 
cult to  see  that  this  deviation  from  the  general  method  is 
no  improvement.  The  further  from  the  centre  the  meiler 
is  kindled  the  less  the  interior  parts  of  the  meiler  will  be 
heated,  the  more  the  coaling  process  will  confine  itself  to 
the  exterior  parts  of  the  meiler,  and  the  final  result  will 
be  that  we  get  a  larger  quantity  of  brands. 

When  the  fire  comes  out  at  the  foot  the  uncoaled  ends 
of  billets  found  there  are  taken  out,  and  the  place  is  cov- 
ered with  dust  as  tight  as  possible  to  prevent  consumption. 
The  meiler  should  now  be  coaled  blind  for  about  a  day,  in 
order  that  the  temperature  may  be  somewhat  reduced. 
Sometimes  the  fire  goes  into  the  offsets,  which,  if  found 
necessary,  is  facilitated  by  loosening  the  dust  above.  In 
conducting  the  heat  into  the  offsets  we  must  be  very  care- 
ful not  to  do  it  too  soon,  and  to  make  the  coaling  process 
follow  the  hearth.  The  coaling  must  have  reached  the 
bottom  of  the  fireplace  before  the  fire  is  conducted  into  the 
offsets. 

After  coaling  blind  about  24  hours  it  is  time  to  open 
three  canals  on  the  upper  side,  in  order  to  conduct  the 
coaling  in  the  offsets  back  to  the  centre.  Of  these  canals 
the  middle  one  is  opened  opposite  the  place  where  the  fire 
is  gone  out,  and  the  two  others  each  about  3  feet  from  the 


HAND-BOOK  FOR  CHARCOAL  BURNERS.        127 

former  if  the  hearth  is  steep,  but  if  it  is  nearly  horizontal 
they  should  be  opened  about  10  to  15  feet  from  the  cen- 
tral canal.  This  difference  in  the  position  of  the  canals  to 
each  other  is  explained  by  the  fact,  that  the  steeper  the 
hearth  is,  the  more  concentrated  draught  is  required  from 
the  upper  side  to  conquer  the  disinclination  of  the  coaling 
•process  to  go  up  hill  and  hinder  it  from  spreading  prema- 
turely to  the  sides,  by  which  the  heart  of  the  meiler  would 
remain  uncoaled.  It  depends  especially  upon  having  the 
fire  properly  conducted  into  the  walls  and  protecting  these 
from  consumption,  whether  the  coaling  shall  be  good  or 
poor ;  the  greatest  skill  and  attention  are  required  on  the 
part  of  the  collier,  in  order  that  the  drawing  back  of  the 
coaling  process  may  be  neither  too  weak  nor  too  violent. 
If  the  former  is  the  case,  the  meiler,  as  has  already  been 
stated,  will  not  be  coaled  in  the  centre  ;  and  if  the  latter 
is  the  case  we  will  get  weak  charcoal  on  the  lower  side  of 
the  hearth  near  the  fireplace.  For  the  latter  reason  some 
meilers  cannot  have  any  canals  opened  on  the  upper  side 
at  all. 

When  the  coaling  has  going  so  far  back  that  the  cover- 
ing begins  to  settle  above  the  centre,  the  three  canals  should 
be  moved  farther  apart  and  new  ones  opened  farther  out 
along  the  foot  of  the  meiler,  at  which  time  most  colliers 
also  open  smoke- vents,  while  others,  on  the  other  hand,  re- 
gard this  as  unnecessary  or  even  injurious.  These  smoke- 
vents  and  canals  should  not,  however,  for  the  protec- 
tion of  the  charcoal,  be  placed  at  a  less  distance  than  5 
to  6  feet  from  the  horseshoe  offsets,  which  of  course,  as  the 


128  HAND-BOOK   FOR   CHARCOAL   BURNERS. 

coaling  progresses,  gradually  extend  more  and  more  upward 
and  outward.  If  we,  on^he  other  hand,  open  smoke- vents 
immediately  above  the  offsets,  as  is  sometimes  done,  espe- 
cially in  the  western  part  of  Vermland,  then  the  gases 
formed  in  the  meiler  are  drawn  thither  and  have  a  com- 
sumptive  effect  upon  the  charcoal,  which  therefore  becomes 
porous  and  weak.  Hence  the  smoke  ought  especially  to 
be  conducted  out  on  the  upper  side.  By  opening  smoke- 
vents  near  the  brow,  which  are  afterwards  gradually  moved 
down,  the  coaling  is  made  to  progress  as  in  other  standing 
meilers,  from  above  downwards.  On  the  other  hand,  if  no 
smoke-vents  are  made,  most  of  the  coaling  will  be  done 
in  the  offsets  themselves,  whereby  these  become  more  steep, 
so  that  hollow  places  may  easily  be  formed  on  the  dividing 
line  between  the  wood  and  the  charcoal,  and  the  meiler 
thus  becomes  more  difficult  to  manage.  This  disadvantage 
usually  presents  itself  in  the  Vermland  meiler,  which  there- 
fore demands  more  constant  care  than  the  other  standing 
meilers.  When  the  coaling  toward  the  end  has  reached 
half  way  down  the  billets,  we  open  still  more  canals.  It 
needs  scarcely  be  mentioned  that  during  the  whole  time 
of  coaling  the  dust  should  be  loosened  in  front  of  the  place 
where  the  coaling  process  is  going  on,  but  on  the  con- 
trary be  well  packed  down,  where  coaling  is  done  and 
where  cracks  are  apt  to  be  formed  on  account  of  the  irregu- 
lar progress  of  the  coaling  process  in  this  kind  of  meiler. 
Brands  at  the  foot  of  the  meiler  are  taken  out  immediately 
after  the  coaling  has  reached  this  place,  which  is  then 
closed  with  thoroughly  cleaned  fine  and  tight  dust.  This 


HA.ND-BOOK   FOE   CHARCOAL    BURNERS.  129 

is  the  usual  process  of  coaling,  when  it  is  conducted  back 
into  both  the  offsets.  But  it  is  also  customary,  when  the 
fire  gets  out  at  the  foot  of  the  meiler  on  the  lower  side,  to 
conduct  the  coaling  back  only  into  the  offset  toward  the 
upper  side,  and  from  there  conduct  it  down  again  on  the 
other  side.  This  is  done  by  keeping  the  offset  that  is  to 
be  saved  well  packed  and  free  from  draught,  while  the 
dust  is  loosened  over  and  in  front  of  the  offset  in  which 
we  want  the  coaling  to  go  on.  When  in  the  latter  offset 
the  coaling  has  reached  near  the  upper  side,  the  nearest 
canal  is  closed,  and  one  or  more  others  are  opened  in  the 
direction  which  we  now  want  the  fire  to  take  down  to  the 
hearth.  As  the  coaling  now  gradually  progresses  down 
the  slope,  the  canals  are  gradually  moved  farther  down, 
until  finally  the  last  canal  is  made  on  the  lower  side,  and 
when  the  fire  is  seen  there  too,  the  coaling  is  finished.  In 
this  method  of  conducting  the  coaling  first  up  to  the  upper 
side,  and  then  down  again  to  the  lower  side,  no  smoke- vents 
are  used,  but  the  dust  is  loosened  as  usual  opposite  the 
place  where  the  coaling  process  is  in  operation — that  is  to 
say,  opposite  the  offset.  This  manner  of  conducting  the 
coaling  around  only  in  the  one  offset  is  the  most  common. 
We  almost  always  get  in  this  manner  better  and  stronger 
charcoal  in  that  part  of  the  meiler  where  the  coaling  is 
last  conducted  downward,  which  comes  partly  from  the  fact 
that  the  billets  there  have  become  more  thorougly  dried, 
while  the  coaling  has  progressed  upward  on  the  opposite 
side,  and  partly  from  the  fact  that,  as  has  been  stated  sev- 
eral times,  the  coaling  proceeds  more  naturally  and  easily 
6* 


130  HAND-BOOK   FOR   CHARCOAL    BURNERS. 

down  a  slope  than  upward.  It  has  also  been  found  that 
if  the  fire  is  conducted  into  both  the  offsets,  it  easily  be- 
comes so  hot  and  spreads  so  much  that  the  draught,  heat, 
etc.,  cannot  be  properly  regulated,  whereby  the  coaling  is 
done  too  fast  and  loss  of  charcoal  cannot  be  avoided.  It  is 
stated  above  that  before  the  fire  is  conducted  into  the  off- 
sets, it  should  have  come  out  at  the  foot,  but  in  opposition 
to  this  theory  some  claim  that  the  fire  should  be  let  out  at 
the  brow  and  be  conducted  thence  to  one  side,  while  if  the 
fire  is  permitted  to  go  down  to  the  foot  in  the  beginning 
the  metier  will  be  exposed  to  consumption. 

In  coaling  according  to  the  Vermland  method  there  is 
most  always  a  large  quantity  of  fuel  lost  in  the  fireplace, 
while,  if  the  collier  does  not  understand  well  the  consider- 
ably complicated  management  of  the  meiler,  the  charcoal 
on  the  lower  side  generally  becomes  porous  and  inferior, 
and  besides  this  a  lot  of  brands  is  produced. 

8.  LYING  MEILERS. 

The  Common  Swedish  Lying  Meilcr. 

In  all  the  meilers  which  have  now  been  described  the 
billets  are  put  up  more  or  less  vertically,  wherefore  they 
are  called  standing  metiers,  but  in  Sweden  and  especially 
in  Dalarne,  meilers  are  used  in  which  the  billets  are  laid 
horizontally,  and  which  for  this  reason  are  called  lying 
meilers.  They  are  in  so  many  respects  essentially  different 
from  the  standing  meilers  that  they  form  as  it  were  a  sepa- 
rate class  in  contradistinction  to  the  stand \i\grneilcrs.  But 


HAND-BOOK   FOR    CHARCOAL   BURNERS.  131 

the  lying  meiler  is  also  in  many  respects  like  the  standing 
meiler,  hence  in  the  following,  for  the  purpose  of  avoiding 
unnecessary  repetitions,we  will  frequently  refer  to  what  has 
been  said  before,  and  when  reference  is  made,  if  nothing 
to  the  contrary  is  said,  it  will  be  to  the  Swedish  standing 
meiler  on  a  horizontal  hearth  with  chimney. 

The  Hearth  and  Billets. 

In  regard  to  the  preference  of  old  hearths,  the  prepara- 
tion of  new  ones,  and  in  regard  to  the  conditions  necessary 
to  make  a  hearth  good,  we  may  refer  generally  to  what  has 
been  stated  heretofore,  excepting  that  the  hearth  of  the 
lying  meiler,  like  that  of  the  two  standing  meiler ls  last  de- 
scribed, is  made  somewhat  sloping  ;  hence  it  is  easier  to  find 
suitable  hearths  for  lying  metiers,  and  their  preparation  re- 
quires less  work  and  expense.  This  sloping,  by  which  at 
least  this  advantage  is  gained,  that  the  water  discharged 
upon  the  hearth  during  the  coaling  process  more  easily 
runs  off,  is  usually  1  to  1^  feet  fur  a  meiler  20  feet  long 
from  the  lower  side,  where  the  kindling  is  done,  to  the 
upper  side.  Much  sloping  should  be  avoided,  for  then  it 
will  be  difficult  to  conduct  the  fire  or  coaling  process  from 
the  lower  side,  which  we  will  now  call  the  "  foot,"  to  the 
upper  side,  which  we  will  call  the  "  rear." 

The  length  of  the  billets,  usually  20  to  24  feet,  determines 
the  breadth  of  the  meiler  between  the  gables,  or,  in  other 
words,  the  lengths  of  the  foot  and  rear  of  the  hearth,  both 
of  which  will  therefore  be  the  same,  since  in  every  meiler 
only  billets  of  about  the  same  length  are  used.  Both 


132  HAND-BOOK   FOR   CHARCOAL   BURNERS. 

of  these  extremes  of  the  meiler  should  be  horizontal  and 
parallel  with  each  other,  whereby  the  hearth  will  get  a 
rectangular  form  and  present  a  sloping  plane.  The  slope 
of  the  plane  should  be  equal  to  the  slope  of  both  the  sides 
of  the  rectangle,  which  are  perfectly  parallel  to  each  other. 
Sometimes  the  length  and  breadth  of  the  meiler  are  the 
same,  but  usually  the  distance  between  the  foot  and  the 
rear  is  4  to  5  feet  greater  than  the  distance  between  the 
gables.  The  work  in  building  the  metiers  is  facilitated  if 
there  is  a  sloping  elevation  of  ground  above  it,  for  unload- 
ing the  billets,  from  which  they  can  be  rolled  into  the 
meiler.  As  has  already  been  stated,  billets  of  different 
length  are  used  in  different  meilers.  In  localities  where 
the  timber  is  very  large,  or  where  it  is  not  possible  to 
make  a  hearth  of  the  usual  length,  we  make  the  billets 
somewhat  shorter,  although  the  capacity  of  the  meiler  is 
thereby  decreased,  and  the  expense  of  watching  and  other 
work  will  be  increased  in  proportion  to  the  charcoal  pro- 
duct. It  is  of  great  importance  to  cut  the  limbs  off  close 
to  the  stem  ;  in  the  next  place  it  is  advantageous  to  cut  the 
billets  off  with  a  saw.  while,  without  regard  to  the  sawing  of 
wood,  the  gables  of  the  meiler  will  be  more  smooth.  The 
rule  that  the  billets  ought  to  be  of  the  same  length  must 
not  be  taken  too  literally,  for  in  order  to  make  the  meiler 
sufficiently  tight  it  is  necessary,  as  will  be  shown  below,  to 
use  a  considerable  quantity  of  more  or  less  long  small  wood  ; 
for  which  purpose  we  utilize  the  tops  of  trees,  waste  wood, 
branches,  etc.  Large  stems  should  also  be  cut  off  where 
there  are  crooks  and  joints.  It  is  not  customary  to  split  the 


HAND-BOOK   FOE   CHARCOAL   BURNERS.  133 

large  green  stem- wood,  and  it  would  generally  require  too 
much  work  and  be  almost  impossible  with  curly-grained 
wood.  Yet  hollow  stems  should  be  split,  unless  we  fill 
them  with  small  wood,  for  otherwise  an  injurious  draught 
in  the  meiler  may  easily  arise.  In  regard  to  the  felling, 
seasoning,  etc.,  of  the  timber  it  is  not  necessary  to  add  any- 
thing special. 

Building  and  Thatching  of  Meiler. 

When  the  hearth  has  been  selected  and  the  place  of  the 
meiler  has  been  determined  by  laying  out  poles  on  all  sides, 
the  building  of  the  meiler  begins  by  laying  down,  length- 
wise the  hearth,  3  or  4  straight  poles,  so  long  that  they  will 
reach  from  the  foot  of  the  meiler  to  about  1^  feet  beyond 
the  rear.  Their  butt-ends,  which,  according  to  the  greater 
or  less  firmness  of  the  hearth,  ought  to  measure  from  4  to 
7  inches  in  diameter,  are  all  laid  upwards.  Furthermore 
it  should  be  observed  that  to  the  exterior,  poles  should  lie 
about  2  feet  inside  of  the  gables,  and  all  should  be  about 
the  same  distance  from  each  other.  The  object  of  these 
poles  or  beams  is  to  prevent  the  billets  from  sinking  into 
the  ground. 

Along  the  foot  we  put  down  firmly  as  a  support  for  the 
billets  2  or  3  posts,  which  are  made  to  lean  over  the 
hearth  with  a  slope  of  about  5  inches,  and  which  are  of 
the  same  height  as  the  meiler  is  to  be.  Against  these 
posts  we  now  begin  to  pile  up  the  billets  across  the  poles, 
and  the  billets  are  sorted  in  such  a  manner  that,  as  is 
shown  in  Figure  7,  the  smallest  and  driest  part  of  them  get 


134 


HAND-BOOK   FOR   CHARCOAL    BURNERS. 


their  place  on  the  lower  side  of  the  hearth,  from  the  foot 
to  the  brow  and  inside  of  it. 


FIG.  7. 

We  also  put  small,  dry  billets  on  the  poles  along  the 
whole  hearth,  and  in  the  roof,  as  the  upper  part  of  the 
meiler  is  called,  between  the  brow  and  the  rear  wall. 
The  large  billets  are  therefore  put  partly  in  the  interior  of 
the  meiler,  and  partly  against  the  rear  wall.  We  should 
take  special  care  to  make  the  side  walls  or  gables  perpen- 
dicular, and  at  the  same  time  quite  free  from  holes  or 
projecting  ends  of  billets.  In  the  whole  building  of  the 
meiler  both  the  gables  should  be  kept  the  same  height, 
which  is  done  by  laying  the  billets  with  the  butt-ends  alter- 
nately with  respect  to  the  gables.  All  hollow  places  be- 
tween the  large  billets  are  filled  as  well  as  possible  with 
tops,  twigs,  and  other  small  wood.  The  roof  should  rise 
gradually  from  the  brow  to  the  top,  as  steep  as  can  be, 
without  the  billets  rolling  down. 

Although  it  is  sometimes  customary  to  kindle  the  meiler 


HAND-BOOK   FOR   CHARCOAL    BURNERS.  135 

at  the  brow  or  a  little  above  it,  still  it  is  more  customary 
and  more  convenient  to  do  it  in  a  horizontal  drum  made 
for  this  purpose,  6  to  8  inches  in  diameter,  extending  from 
one  gable  to  the  other,  about  one  foot  below  the  brow  and 
one  foot  from  the  lower  side.  This  drum  is  filled  while 
building  the  meiler  with  fine  split  dry  wood  or  fine  split 
brands  that  are  easily  ignited. 

When  the  whole  hearth  has  been  covered  with  one 
layer  of  billets,  we  lay  down  in  the  rear  the  first  wall- 
block,  and  6  inches  from  this  the  so-called  dust-block. 
Both  these  blocks  are  mortised  with  the  beams  or  poles 
on  the  hearth,  in  order  that  they  may  be  firm.  For  this 
purpose,  as  for  all  the  other  wrall-blocks,  which  together 
form  the  rear  wall  of  the  meiler,  which  slopes  a  little  in- 
ward, we  select  straight  blocks  of  wood,  without  limbs, 
and  8  to  10  inches  in  diameter.  Into  two  niches  cut  into 
the  lower  wall-block,  we  lay  across  the  billets  about  3  feet 
from  the  ends  of  the  blocks  two  wedges,  Fig.  8,  for  which 
we  take  tops  of  trees,  3  feet  long  and  3  to  4  inches  in 


diameter,  provided  with  corresponding  niches.  Into  these 
wedges  we  then  lay  the  next  wall-block,  and  so  on  up  the 
whole  rear  wall,  whereby  the  latter  becomes  firmly  con- 
nected with  the  interior  of  the  meiler,  and  hence  it  gets 
sufficient  strength  to  resist  the  pressure  and  weight  of  the 


136  HAND-BOOK   FOR    CHARCOAL    BURNERS. 

billets,  the  explosions  of  the  meiler,  etc.  By  these  wedges, 
which  taper  toward  the  smaller  end  which  is  put  into  the 
meiler,  there  is  also  formed  at  every  wall-block  from  the 
rear  wall  inward  a  nearly  horizontal  opening;,  through 
which,  during  the  coaling  process,  the  meiler  smoke  escapes 
more  easily,  when  smoke-vents  are  made  in  these  open- 
ings. In  order  to  keep  the  dust  on  better,  and  possibly 
also  to  facilitate  the  coaling,  the  rear  wall  should  slope  in- 
ward a  little,  as  has  already  been  stated,  but  this  slope  is 
gradually  greater,  so  that  the  exterior  of  the  meiler  gets  a 
rounded  form  at  the  top. 

When  the  whole  meiler  has  been  built,  and  the  roof  has 
been  made  tight  with  small  wood,  all  openings  in  the 
gables  are  closed  with  suitably  short  wood.  When  the 
hearth  is  25  feet  long,  the  frcnt  wall  should  be  about  5, 
the  rear  wall  11  to  12,  and  the  top  about  14  feet  high. 
The  top  should  be  5  to  6  feet  inside  of  the  rear  wall. 
Here  it  should,  however,  be  noticed  that,  for  reasons  which 
will  be  given  hereafter,  some  colliers  prescribe  a  lower 
front  side  and  steeper  roof.  The  roof  may  then  be  pre- 
vented from  falling  down  by  laying  lengthwise  2  or  3 
poles  fastened  with  wrillovvs,  the  ends  of  the  poles  placed 
between  the  billets,  while  the  meiler  is  building. 

The  roof  of  the  lying  meiler  is  thatched  with  brush- 
wood the  same  thickness  as  that  put  on  the  cover  of  a 
standing  meiler.  The  brushwood  should  hang  down 
somewhat  both  at  the  rear  wall  and  at  the  brow.  Further- 
more we  put  brushwood  into  all  cavities,  which  are  yet  to 
be  found  between  the  ends  of  the  billets  at  the  gables  of 


HAND-BOOK   FOR    CHARCOAL    BURNERS. 


13T 


the  meiler,  in  order  that  the  dust  may  not  fall  down 
among  the  billets;  likewise  we  put  brushwood  into  all 
cavities  formed  by  the  wall-blocks  in  the  rear,  nor  does  it 
do  any  harm  to  give  the  whole  gables  from  the  bottom  to 
the  top  a  continuous  thin  covering  of  brushwood.  Be- 
tween the  brow  and  the  foot  brushwood  is  not  necessary, 
if  the  billets  are  sufficiently  small  and  piled  closely. 

The  dust  is  usually  thrown  upon  the  roof  first,  but  not 
thicker  than  4  or  5  inches  to  begin  with,  in  order  that  the 
steam  during  the  first  days  of  coaling  may  escape  more 


FIG.  9. 


easily.  Then  the  four  sides  are  covered  with  dust  simul- 
taneously, but  special  arrangements  are  now  necessary  to 
keep  the  dust  on  the  gahle  ends.  For  this  purpose  we 
put  up  in  a  slanting  position  against  the  gables  three 
posts  on  each  side  somewhat  higher  than  the  meiler  (Fig. 
9),  about  8  inches  from  the  ends  of  the  billets. 


138  HAND-BOOK   FOR   CHARCOAL    BURNERS. 

Against  these  posts  we  lay  the  gable-wood,  which  con- 
sists of  small,  straight  boards  or  split  billets,  so  long  that 
they  extend  somewhat  beyond  the  mciler  at  both  ends. 
The  lower  board  is  laid  on  a  few  stones,  4-  inches  high,  in 
order  that  it  may  be  possible  to  open  canals  underneath, 
wherever  we  wish. 

On  the  front  side  we  proceed  in  the  same  manner  by 
putting  up  split  billets  against  two  smaller  posts  put  up  in 
the  same  manner.  But  it  is  not  necessary  here  to  leave 
any  space  between  the  ground  and  the  split  billets. 

As  the  covering  with  dust  progresses  from  below  up- 
ward we  put  in  i  ore  and  more  split  billets;  and  we 
must  see  that  the  dust  is  free  from  chips,  turf,  small  char- 
coal, etc.,  and  that  it  is  packed  close  to  the  wood,  so  that 
there  may  nowhere  be  any  concealed  draught.  For  it 
often  happens,  if  the  dust  is  not  clean  or  is  packed  care- 
lessly, that  the  fire  gets  out  to  the  covering  wood  and  burns 
it  up,  so  that  the  dust  falls  down  and  the  billets  become 
bare ;  this  always  causes  inconvenience  and  damage. 
[Holes  are  left  open,  through  the  side  covering  to  the 
kindling  drum,  by  a  few  pieces  of  wood  that  sustain  the 
dust.] 

The  rear  wall  should  slant  sufficiently  to  allow  the  dust 
to  be  put  on  with  the  aid  of  side-blocks,  about  as  we  do  it 
with  the  standing  metier.  A  close  wall  of  split  billets 
would  not  do  on  this  side,  since  we  here  have  to  open 
smoke-vents.  The  lower  wall-block,  mentioned  above, 
serves  as  the  lower  block  to  sustain  the  dust,  and  the 
other  blocks  are  put  on  above,  as  close  together  as  the 


HAND-BOOK    FOE    CHARCOAL    BURNERS.  139 

case  may  require.  Each  block  should  be  made  at  least  as 
long  as  the  meiler  is  wide,  in  order  that  its  ends  may 
extend  nearly  to  the  side  walls  of  split  billets,  and  be  pro- 
vided with  two  braces. 

The  most  important  thing  in  putting  on  the  dust  cover- 
ing is  that  the  dust,  thoroughly  cleansed,  should  be  packed 
tight  everywhere,  and  especially  in  the  corners,  and  be  put 
on  sufficiently  thick,  at  least  half  a  foot.  All  posts  and 
blocks  should  be  braced  so  securely  that  none  of  them  get 
out  of  place,  even  though  the  meiler  should  explode  some- 
what. 

The   Watching  of  the  Meiler. 

The  kindling  is  done  in  still  weather,  at  either  end  of 
the  kindling  drum  ;  in  case  of  wind,  it  should  not  be  kin- 
dled on  the  windward  side.  When  the  fire  has  progressed 
into  the  meiler  one-third  of  its  breadth,  the  kindling  canal 
is  closed  with  brushwood  and  dust,  and  well  packed, 
while  the  drum  is  still  kept  open  at  the  other  gable-end 
where  the  air  enters  in  the  direction  opposite  that  in 
which  the  fire  progresses.  By  loosening  the  dust,  and 
opening  small  smoke- vents  above  the  brow,  we  facilitate 
the  progress  of  the  fire  in  this  direction,  until  it  finally 
shows  itself  at  the  other  end  of  the  drum,  when  this  also 
is  closed  with  brushwood  and  dust.  The  smoke-vents  are 
gradually  moved  ahead  of  the  fire,  and,  on  the  other  hand, 
the  dust  is  packed  down  again  as  far  as  the  fire  has  gone. 

The  fire  may  also  be  built  simultaneously  at  both  ends 
of  the  drum,  and  afterwards  be  conducted  to  the  centre 


140        HAND-BOOK  FOR  CHARCOAL  BURNERS. 

from  both  sides ;  but  in  this  method  of  coaling,  as  the 
draught  during  the  whole  time  passes  through  the  parts 
that  have  already  been  kindled,  more  wood  is  lost,  arid  the 
charcoal  around  the  kindling  drum  becomes  looser. 

If  the  billets  are  quite  dry,  the  kindling  can  be  done  in 
less  than  24  hours.  If  the  billets  are  green,  more  time 
is  required,  about  48  hours.  Then  it  frequently  happens 
that  the  fire,  where  it  has  already  become  established,  has 
a  tendency  to  get  to  the  roof  too  soon,  which  should  be 
prevented  by  opening  a  few  canals  at  the  foot  below  this 
place,  whereby  the  fire  will  be  made  to  take  a  more  down- 
ward direction. 

When  the  whole  drum  is  kindled,  these  canals  should 
be  closed  immediately.  When  all  the  openings  have  been 
tightened  with  dust,  and  considerable  air  is  still  needed  to 
sustain  the  fire,  or  coaling  process,  then  it  is  necessary,  in 
order  to  understand  the  coaling  process  properly,  to  ex- 
plain first  in  what  manner  the  air  gets  into  the  meiler. 
It  does  not  get  in  through  holes  opened,  for  it  is  some- 
thing peculiar  to  tin's  method  of  coaling  that  canals,  other- 
wise than  exceptionally,  are  not  needed  before  the  greater 
part  of  the  meiler  has  been  coaled.  The  air  comes  in 
wherever  it  can,  through  the  hearth,  if  this  is  not  tight,  at 
the  foot,  at  the  rear,  and  at  the  gable-ends.  Most  air  en- 
ters at  the  foot  to  begin  with,  but  afterwards  mostly- 
through  the  gables,  where  the  dust  cannot  avoid  becoming 
more  or  less  loose,  on  account  of  the  drying  and  coaling  of 
the  billets,  and  the  shrinkage  thus  produced. 

The  thoroughly  dry  dust,  of  course,  settles  in  propor- 


HAND-BOOK   FOR   CHARCOAL    BURNERS. 

tion  if  it  is  sufficiently  fine,  and  hence  it  would  not  be 
right  to  insist  that  any  real  openings  are  formed  in  this 
wise  under  ordinary  circumstances ;  but  we  ought  at  least 
be  permitted  to  say  that  on  account  of  the  shrinkage  of 
the  wood  the  dust  at  the  end  of  the  billets  is  loosened  as 
it  were  and  thus  becomes  more  easily  penetrated  by  the 
air  than  the  dust  cloak  on  a  standing  meiler,  which  is  well 
packed  down,  and  everywhere  accessible  to  the  collier. 

In  the  same  manner  as  the  standing  meiler^  the  lying 
meiler,  also  immediately  after  kindling  and  later,  develops 
a  large  quantity  of  steam,  which  partly  condenses  on  the 
cold  billets  and  runs  down  to  the  hearth,  and  partly  makes 
its  way  up  through  the  dust-roof,  which  therefore  becomes 
damp,  and  must  for  this  reason  often  need  raking  into. 
This  is,  in  short,  the  beginning  of  the  lying  meiler's  sweat- 
ing. If  the  dust  is  now  kept  tight  and  heavy,  the  meiler 
will  have  a  tendency  to  explode. 

Sometimes  the  fireplace  near  the  brow  is  fed  and  en- 
larged by  the  air  rushing  to  that  place,  while  the  nitrogen 
and  the  gaseous  products  of  combustion  make  their  way 
up  through  the  roof.  What  would  now  be  the  process  of 
coaling  if  it  were  left  to  itself  ?  About  the  same  as  in  the 
Yermland  stan ding  meiler,  when  the  fire  is  there  conducted 
back  into  the  offsets  ;  but  with  this  important  difference, 
that  on  account  of  the  horizontal  position  of  the  billets, 
and  their  still,  almost  cold  condition,  the  offsets  would  be 
more  steep,  and  hence  the  meiler  would  be  more  difficult 
to  manage.  A  large  quantity  of  wood  would  burn  up, 
and  a  large  quantity  remain  uncoaled.  The  principal 


HAND-BOOK   FOR    CHARCOAL   BURNERS. 

point  for  the  collier  is  to  provide  against  such  a  coaling 
in  offsets,  which  he  does  more  or  less  perfectly  by  partly 
checking  in  time,  as  far  as  possible,  the  progress  of  the 
coaling  deep  into  the  meiler,  inside  the  brow  and  foot,  and 
partly  by  conducting  the  coaling  rapidly,  and  in  the  ex- 
terior layer  of  billets,  from  the  brow  over  the  covering  to 
the  rear  wall. 

The  progress  of  the  fire  from  the  kindling  drum  down 
to  the  hearth,  toward  the  draught  coming  from  below, 
cannot  be  prevented,  nor  does  it  do  any  harm  ;  that  is  to 
say,  it  does  not  cause  steep  settlings  or  offsets  ;  but  the  heat 
and  draught  can  be  so  regulated  that  the  fire  does  not 
penetrate  more  than  2  or  3  feet  into  the  meiler.  For  this 
purpose,  it  is  well  to  keep  the  dust  tight  and  well  packed, 
both  above  and  along  the  roof  where  the  kindling  is  done, 
and  down  along  the  front  to  the  foot,  and  likewise  down 
along  the  gables.  It  is  easy  to  understand  that  the  higher 
above  the  hearth  we  put  the  kindling  drum,  the  more  the 
fire  will  have  an  opportunity  to  spread  before  it  reaches 
the  hearth,  wherefore,  as  has  been  said  in  passing,  some 
colliers  prescribe  a  height  of  only  3  to  4  feet  on  the  front 
side. 

When  the  fire  has  got  well  down  to  the  hearth,  and  the 
charcoal  has  been  packed  down  there,  we  need  not  fear 
that  the  coaling  will  penetrate  too  far  into  the  meiler 
from  there. 

But  if  this  has  happened  earlier,  then  the  coaling  pro- 
cess usually  progresses  far  into  the  billets  toward  the  rear 
wall,  and  then  offsets  are  unavoidable. 


HAND-BOOK   FOR    CHARCOAL   BURNERS.  143 

Upon  the  whole,  the  more  the  fire  spreads  between  the 
brow  and  the  foot,  the  looser  charcoal  we  get,  on  account 
of  the  very  high  coaling  temperature  and  the  increased 
difficulty  of  protecting  the  glowing  coals  properly  from 
all  draught.  It  may  then  be  that  from  a  fourth  to  a  third 
part  of  the  metier,  from  the  front  towards  the  rear,  pro- 
duces only  small  and  loose  charcoal. 

(  Then  it  was  said  the  metier  should  be  so  managed  that 
the  exterior  of  its  roof  coals  quickly.  For  this  purpose 
we  open  a  few  smoke-vents  across  the  roof,  a  suitable  dis- 
tance from  the  brow ;  which  smoke- vents  are  afterwards 
gradually  moved  as  the  roof  coals,  up  to  the  covering,  and 
then  further  on  to  the  upper  wall-block. 

It  is  also  customary,  though  it  obviously  requires  more 
work,  to  keep  the  dust  shovelled  off  a  broad  strip,  which  is 
moved  as  the  coaling  progresses,  so  that  it  continually  re- 
mains 5  to  6  feet  ahead  of  the  place  where  the  coaling 
process  is  in  operation.  It  is  also  claimed  that  the  whole 
roof  may,  without  disadvantage,  be  coaled  uncovered,  but 
we  must  then  put  on  dust  gradually  from  below  upwards, 
as  fast  as  the  fire  progresses ;  the  putting  on  of  the  dust 
should,  however,  of  course,  be  so  far  ahead  of  the  coaling 
process  as  is  necessary  to  protect  the  charcoal  from  con- 
sumption. When,  as  has  been  stated  above,  some  colliers 
prescribe  a  roof  so  steep  that  it  must  be  tied  together  so 
as  not  to  fall  down,  we  must  bear  in  mind  that  this  is  to 
facilitate  and  hasten  the  coaling  of  the  roof.  It  seems, 
however,  that  this  method,  by  which  there  is  danger  that 
the  metier  may  get  out  of  shape,  ought  not  to  be  necessary, 


344  HAND-BOOK   FOR    CHARCOAL   BURNERS. 

as  the  same  end  can  be  obtained  by,  as  has  been  explained, 
keeping  the  dust  off  a  greater  or  less  portion  of  the  roof. 
Whatever  method  we  adopt  for  the  escape  of  the  smoke, 
the  place  of  escape  should  always  be  so  far  from  the  fire 
or  coaling  process,  that  the  thin,  transparent  smoke  has  a 
light  bluish-white  color.  When  the  color  of  the  smoke 
grows  bluer,  then  it  is  time  to  move  the  smoke-vents  or 
the  strip  shovelled  off  further  toward  the  rear.  If,  on  the 
other  hand,  the  smoke  is  made  to  escape  too  far  away  from 
the  \joaling  part  of  the  roof,  it  frequently  happens  that 
the  coaling  goes  far  down  into  the  billets,  which  is  the 
very  thing  we  try  to  avoid.  In  all  coaled  places  the  dust 
is  packed  down  well  and  increased  to  at  least  6  inches 
thickness. 

In  the  next  place,  we  must  see  that  the  coaling  progresses 
uniformly  along  the  whole  breadth  of  the  roof.  When  it 
has  a  tendency  to  get  ahead,  the  dust  should  be  kept  less 
loose ;  while  the  latter  should  be  loosened  more  and  more. 
Smoke-vents  are  opened  in  places  where  the  coaling  is  be- 
hind. When  the  coaling  progresses  too  slowly  or  the  ends 
of  the  billets  are  imperfectly  coaled,  and  for  this  reason 
will  not  settle,  then  a  few  canals  are  opened  at  the  foot  of 
the  gables,  which  must  not,  however,  be  kept  open  any 
longer  than  is  necessary. 

When  the  roof  between  the  front  side  and  the  covering 
has  been  coaled  arid  packed  down,  the  coaling  is  con- 
ducted from  the  roof  to  the  hearth  by  smoke-vents,  opened 
gradually  farther  and  farther  down  in  the  rear  wall.  The 
meiler  is  now  managed  about  like  the  standing  meiler 


HAND-BOOK   FOR   CHARCOAL   BURNERS.  145 

after  the  covering  of  the  latter  has  been  coaled.  First, 
the  smoke-vents  are  opened  along  the  upper  wall-block 
about  1  to  2  feet  from  each  other,  after  which  the  roof 
between  the  covering  and  the  rear  wall  soon  settles. 
During  the  rest  of  the  coaling  process  we  keep  a  careful 
lookout  that  the  roof  is  everywhere  kept  tight  and  free 
from  draught. 

From  the  appearance  of  the  smoke  we  decide  when  the 
smoke- vents  are  to  be  moved  down  to  the  next  wall-block. 
This  should  be  done  as  soon  as  the  smoke  assumes  a 
blue  color.  If  it  is  done  sooner,  a  part  of  the  billets 
will  remain  un coaled,  if  later,  a  part  of  the  charcoal 
will  be  consumed.  When  the  coaling  process  has  got 
down  a  short  distance,  smoke-vents  are  usually  opened  at 
2  or  3  wall-blocks  simultaneously.  The  more  sluggishly 
the  coaling  progresses  and  the  more  uncoalcd  billets  are 
left  in  the  meiler,  which  may,  among  other  things,  be  de- 
termined by  the  manner  in  which  the  roof  settles,  the 
more  smoke-vents  should  be  opened.  When  the  coaling 
process  has  reached  at  least  half  way  down  the  rear  wall, 
more  air  is  required  from  the  hearth,  which  is  obtained 
by  opening  at  the  foot  of  the  rear  wall  a  few  (usually  4  to 
begin  with)  canals,  the  number  of  which  is  increased 
the  nearer  the  coaling  approaches  the  hearth.  As  neces- 
sary as  these  canals  now  are,  just  in  the  same  proportion 
is  it  injurious  to  open  them  without  judgment;  for  in- 
stance, before  the  roof  is  coaled.  This  some  colliers,  how- 
ever, do  usually  for  no  other  purpose  than  to  hasten  the  coal- 
ing process.  They  also  do  hasten  it,  but  at  the  expense  of 


146  HAND-BOOK   FOR   CHARCOAL    BURNERS. 

charcoal,  for  the  coaling  temperature  thereby  gets  too 
high,  and  the  result  necessarily  is  that  the  charcoal  gets 
loose. 

As  with  the  standing  meUer,  so  the  number  and  situa- 
tion of  the  canals  should  in  this  meiler  also  be  regulated 
and  moved  according  to  what  is  indicated  by  the  settling. 
Where  the  meiler  settles  slowly,  more  and  larger  canals 
and  smoke-vents  should  be  opened,  while,  on  the  other 
hand,  where  the  coaling  progresses  rapidly,  a  smaller 
number,  or  even  none  at  all,  are  kept  open.  An  even  and 
uniform  settling  everywhere,  so  that  the  roof  does  not 
form  any  hollows  or  offsets,  is  the  fairest  sign  that  the 
coaling  progresses  well  and  regularly. 

Toward  the  close,  when  smoke-vents  have  been  opened 
at  the  lowest  wall-block,  then  still  more  canals  are  opened 
both  at  the  lower  edge  of  the  rear  wall  and  at  the  foot  of 
the  gables,  in  order  that  the  lower  layer  of  billets  may 
coal  as  completely  as  possible.  By  sticking  in  long  chips 
or  small  pieces  of  wood,  that  are  easily  coaled,  we  examine 
in  all  the  canals  whether  it  is  time  to  close  them.  It 
of  tens  happens  when  the  rest  of  the  meiler  is  coaled,  that 
nearest  to  the  exterior  wall  of  split  billets  there  are 
found  un  coaled  ends  of  billets.  With  a  rod  we  then  open 
from  the  roof  so-called  covering-vents  clear  down  to  the 
uncoaled  wood,  after  which  these  covering-vents,  opposite 
corresponding  canals,  are  kept  open  until  the  color  of  the 
smoke  and  the  settling  show  that  the  coaling  is  finished. 

When  the  meiler^  coaled  and  well  packed  down,  has 
stood  undisturbed  2  or  3  days  it  is  ready  to  be  removed.  To 


HAND-BOOK   FOB   CHARCOAL   BURNERS.  147 

seal  a  meiler  of  this  kind  is  scarcely  possible  on  account 
of  the  steep  gables. 

Other  Kinds  of  Lying  Meiler s. 

Mr.  Uhr,  in  his  article  relating  to  experiments  upon  coal- 
ing, gives  an  account  of  a  lying  meiler  which  is  quite  dif- 
ferent from  the  one  we  have  here  described,  and  which  is 
still  used  in  a  few  places.  He  calls  it  "  lying  meiler  with 
wood  on  the  sides  instead  of  split  billets  and  covered  with 
dust  in  the  same  manner  as  standing  meilers"  In  regard 
to  the  building  of  this  meiler  it  must  be  stated  briefly  that 
when  most  of  the  billets  have  been  put  up  on  a  sloping 
hearth  and  the  meiler  has  assumed  the  form  of  a  common 
lying  meiler,  but  with  the  front  nearly  as  high  as  the  rear, 
and  with  both  these  walls  built  with  wall-blocks,  then 
wood  is  piled  up  along  the  gables  of  the  meiler  •  these 
side  walls  thus  formed  must  slope  sufficiently  to  sustain 
the  dust ;  they  are  also  built  with  wall -blocks.  In  the 
four  corners  shorter  wood  is  put  in,  like  rays  as  it  were,  in 
such  a  manner  that  the  meiler  when  it  is  completed  has  a 
square  form  with  rounded  corners  and  a  covering  rounded 
on  all  sides. 

The  kindling  is  done  near  the  foot,  and  the  chief  feature 
of  the  coaling  process  is  that  it  is  conducted  from  here  to 
the  rear  wall,  and  at  the  same  time  through  the  whole  mei- 
ler,  from  the  covering  down  to  the  hearth. 

The  advantage  of  this  arrangement  is  that  we  do  not 
need  any  siding.  But  the  disadvantages  are  far  greater. 
It  cannot  be  avoided,  when  the  billets  are  put  up  with 


14:8  HAND-BOOK   FOR   CHARCOAL   BURNERS. 

wall-blocks  placed  in  different  directions,  that  with  the 
shrinking  of  the  billets  hollow  places  will  be  formed  here 
and  there,  whereby,  as  has  been  before  stated,  the  coaling 
process  may  easily  get  out  of  order,  and  as  it  is  to  be  con- 
ducted across  the  billets  in  the  centre  of  the  meiler,  but  at 
both  the  gables  along  them,  offsets  and  abrupt  settlings 
can  scarcely  be  prevented.  Besides  the  building  of  this 
meiler  being  difficult,  it  involves  loss  of  time. 

Mr.  Uhr  mentions  also  a  single  experiment  of  a  lying 
meiler  built  with  siding.  The  billets  were  put  on  the  slop- 
ing hearth  lengthwise  with  all  the  butt-ends  turned  up- 
ward, but  in  two  tiers,  one  in  front  of  the  other.  One  tier 
contained  billets  15f  feet  long  and  the  billets  in  the  other 
were  13 j-  feet  long,  hence  the  length  of  the  meiler,  29  ^ 
feet.  At  both  ends  were  furthermore  put  up,  to  the  depth 
of  3  to  4  feet  at  the  foot,  other  billets  across  the  hearth 
and  of  the  same  length  as  the  breadth  of  the  meiler.  The 
front  and  rear  walls,  built  in  this  manner,  were  provided 
with  wall-blocks  and  sloped  in  the  manner  heretofore  de- 
scribed so  much,  that  the  dust  could  be  sustained  with  side- 
blocks. 

The  coaling  of  this  meiler,  which  was  done  in  about  the 
usual  way,  was  very  difficult  to  manage,  since  the  shrink- 
age of  the  wood  formed  a  fissure  between  the  two  tiers  of 
billets,  where  the  dust  therefore  fell  down  and  stopped  the 
draught.  When  the  roof  of  the  forward  tier  had  already 
settled  the  rear  half  of  it  lay  perfectly  uncoaled,  and  just 
as  high  as  it  had  been  from  the  beginning.  JVfore  brands 
were  produced  than  usual,  but  otherwise  just  as  much  and 


HAND-BOOK   FOR   CHARCOAL   BURNERS.  149 

just  as  good  charcoal  as  other  lying  meilers  usually  pro- 
duce. Mr.  Uhr  himself  remarks  that  if  the  meiler  had 
consisted  of  only  one  length  of  billets,  its  care  would  in  all 
probability  not  have  been  more  difficult  than  that  of  other 
lying  meilers. 

Since,  therefore,  this  meiler^  in  spite  of  the  great  mistake 
of  making  it  in  two  halves  without  any  real  connection 
with  each  other,  could  give  a  fair  result,  it  would  seem  to 
prove  that  lying  meilers  just  as  well  as  standing  ones 
might  be  coaled  lengthwise  the  billets,  just  as  well  or  even 
better,  than  across  them.  It  would  no  doubt  be  well  to 
make  more  experiments  in  the  direction  pointed  out  by 
Uhr,  especially  as  the  present  coaling  of  the  lying  meiler 
has  this  objection,  that  the  front  of  the  meiler  always  con- 
tains a  greater  or  smaller  quantity  of  poor  charcoal. 

But,  besides  that  a  meiler ',  intended  to  be  coaled  length- 
wise the  billets,  ought  not  to  be  built  in  two  separate  tiers, 
it  cannot  be  right  to  give  the  meiler  two  other  abrupt  off- 
sets by  laying  in  front  and  rear  separate  billets  along  the 
whole  breadth  of  the  meiler  at  right  angle  with  the  other 
billets.  By  applying  in  the  upper  layers  gradually  short- 
er billets  we  ought  to  be  able  to  give  both  the  walls  a  pro- 
per slope  and  rounding  towards  the  covering.  If  the 
gables  are  built  with  wall-blocks,  then  the  siding  is  not 
needed,  and  finally,  as  the  coaling  progresses  far  easier 
down  than  up  a  slope,  the  meiler  should  be  inverted — that 
is  to  say,  the  small  ends  of  the  billets  should  turn  upward, 
and  the  kindling  should  be  done  at  the  upper  end.  A  fire- 
place of  smaller  billets  might  be  made  from  the  place  of 


150  HAND-BOOK    FOR   CHARCOAL   BURNERS. 

kindling  along  the  whole  length  of  the  meiler,  and  the 
coaling  may  be  conducted  and  managed  nearly  in  the  same 
way  as  the  coaling  of  the  Molinder  standing  meiler.  The 
billets  should  be  perfectly  dry.  In  conclusion,  it  may  be 
stated  that  at  a  factory  in  Norrland  rafted  wood  and  slabs 
are  coaled  in  lying  meilers  even  240  to  260  feet  long.  The 
metiers  are  kindled  at  both  ends  and  the  coaling  is  regu- 
lated by  smoke-vents  in  the  covering.  According  to  statis- 
tics, this  method  of  coaling  slabs  produces  a  better  result 
than  their  coaling  in  standing  meilers.  (Annals  of  the 
Iron  Office,  1862,  page  386.) 


HAND-BOOK    FOE   CHARCOAL   BURNERS.  151 


CHAPTER  IV. 

THE   RESULT   OF    COALING. 

Coaling  during  Different  Seasons  of  the  Year. 

THE  best  season  of  the  year  for  coaling  is  indisputably 
when  hearths  as  well  as  wood  are  most  dry — that  is  to  say, 
early  in  the  fall,  and  at  least  not  later  than  October.  (In 
United  States  of  America,  November.) 

During  spring,  if  the  ground  has  not  dried  sufficiently, 
ev\.-.n  meilers  made  of  dry  wood  are  very  liable  to  work 
badly  and  leave  a  quantity  of  brands.  The  warmest  sea- 
son should  be  avoided,  since  the  coaling  then  operates 
slowly  and  irregularly,  greater  care  and  more  labor  are  re- 
quired in  managing  the  meiler,  and  in  many  places  there 
may  be  lack  of  a  supply  of  water,  sufficient  to  sprinkle  the 
dust  and  extinguish  the  charcoal,  to  contend  with. 

Later  in  the  year,  on  the  other  hand,  we  have  both  the 
fall  rains  which  drench  the  hearth  and  wood,  and  also  cold, 
snow  and  storms,  all  of  which  are  detrimental  to  coaling. 
In  addition  to  this  the  meiler  is  always  managed  less  care- 
fully in  the  long,  dark,  and  cold  nights  than  when  the  days 
are  longer  and  the  weather  more  pleasant.  But  worst  of 
all  is,  as  occurs  in  several  localities  to  coal  during  the  cold- 
est season  of  the  year,  before  and  after  Christmas.  This 


152  HAND-BOOK   FOR   CHARCOAL   BURNERS. 

practice  they  try  to  defend  by  asserting  that,  if  the  work 
is  done  earlier,  the  charcoal  will  get  wet  and  damaged ;  an 
argument  which  loses  its  force  if  we  bnild  suitable  sheds 
for  storing  and  preserving  the  charcoal.  Coaling  should 
never  be  done  in  winter,  excepting  on  hearths  on  which 
there  has  been  uninterrupted  coaling  since  the  preceding 
fall,  and  which  therefore  are  dry  and  supplied  with  unfrozen 
dust.  A  meiler  built  on  a  sour  and  cold  hearth,  during  snow 
and  slush,  can,  if  severe  cold  sets  in,  so  that  the  wet  or 
snowy  billets  freeze  and  the  dust  is  chilled,  scarcely  be 
saved  from  burning  up,  and  many  a  collier  has  broken  him- 
self down  by  over-exertion  in  managing  such  winter  meilers. 
Frozen  dust  put  on  in  lumps  cannot  possibly  make  a  suffi- 
ciently tight  covering,  and  hence  the  heat  in  the  meiler 
gets  too  intense  before  the  dust  has  thawed  out  enough, 
and  the  coaling  product  will  be  poor. 

A   Comparison  of  the  Different  Methods  of  Coaling. 

Ever  since  the  middle  of  the  last  century  efforts  have 
been  made  in  Sweden  to  find  out  which  method  of  coaling, 
that  of  the  standing  or  lying  meiler ',  is  more  profitable ;  but 
the  result  of  these  efforts  is,  that  while  one  author  prefers 
the  standing  meiler,  another  gives  his  preference  to  the 
lying  meiler.  The  real  facts  in  the  case  seem  to  be  that 
an  equal  amount  and  equally  good  charcoal  can  be  pro- 
duced by  both  methods  of  coaling.  It  is  also  worthy  of 
notice  that  there  are  whole  districts  where  the  same  colliers 
use  alternately  these  meilers.  In  some  districts  both 
methods  are  used  promiscuously.  If  either  had  any  decid- 


HAND-BOOK   FOR   CHARCOAL    BURNERS.  153 

ed  general  advantage,  then  it  ought  gradually  to  become 
more  extensively  used,  and  crowd  the  other  out.  But  this 
is,  as  has  been  stated,  not  the  case.  Both  metiers  sustain 
their  reputation  in  their  respective  localities,  and  we  have 
already  many  instances  how  wrong  and  unprofitable  it  is 
to  try  to  induce  or  compel  the  colliers  in  any  locality  to 
change  their  method  of  coaling,  which  has  been  used  from 
time  immemorial.  What  we  should  try  to  do  is  this  : — In 
each  locality  we  should  try  to  get  the  method  of  coaling 
which  is  in  vogue  done  correctly  and  intelligently.  For 
although  some  or  other  of  the  different  kinds  of  standing 
metiers  has  a  decided  preference  and  ought,  other  things 
being  equal,  to  produce  equally  good  charcoal  at  less  ex- 
pense, still  it  must  be  admitted,  on  the  other  hand,  that  the 
most  depends  upon  the  proper  preparation  of  the  hearth 
and  billets  and  the  good  management  of  the  metier  in  gen- 
eral. 

"Where  there  is  a  choice,  we  should  undoubtedly  be 
governed  by  local  circumstances.  The  lying  metier  is  bet- 
ter adapted  for  localities  where  there  is  large  and  straight 
coniferous  timber  and  where  there  is  tolerably  even  and 
accessible  ground.  But  where  the  stem  of  the  tree  is  util- 
ized for  lumber,  etc.,  while  the  charcoal  is  principally  made 
of  tops,  limbs,  and  -waste  wood,  the  lying  metier  is  out  of 
place.  It  takes  less  time  to  prepare  the  billets  for  the 
lying  metier,  and  where  the  axe  is  used  there  is  less  wasted. 
They  suffer  less  from  wind  and  cold,  are  more  easily  man- 
aged, and  do  not  require  so  great  skill.  On  the  other 
hand,  their  building,  for  which  two  men  are  needed,  requires 
7* 


154:  HAND-BOOK   FOR   CHARCOAL    BURNERS. 

more  labor.     They  are  not  adapted  for  rough  countries  or 
for  crooked,  f olif erous  timber. 

In  respect  to  the  advantages  and  disadvantages  con- 
nected with  the  different  kinds  of  standing  metiers,  the 
reader  is  referred  to  the  separate  descriptions  of  each  of 
these  metiers,  to  which  there  must  now  only  be  added 
that  the  standing  meiler  on  a  horizontal  hearth  with  a 
chimney  and  the  Vermland  meiler  should  be  preferred, 
when  the  wood  is  sour  or  if  the  coaling  is  to  be  done 
during  winter,  since  at  that  time  it  is  always  necessary 
to  sacrifice  a  considerable  amount  of  wood  in  order  to  give 
the  meiler  the  proper  coaling  temperature — that  is  to  say, 
large  fillings  cannot  be  avoided.  If,  on  the  other  hand, 
the  wood  and  hearth  are  dry  and  the  coaling  is  done  before 
frost  sets  in,  the  meiler  on  a  horizontal  hearth  with  a  cen- 
tre block  has  the  preference. 

The  Size  of  the  Metiers. 

Experience  has  shown  that  small  metiers  usually  do 
best,  but  the  charcoal  then  becomes  dear,  while  different 
expenses,  especially  during  the  watching  of  the  metier,  are 
nearly  the  same  for  a  small  as  for  a  large  one.  Hence 
the  expense  of  making  charcoal  is  generally  less  in  large 
metiers ;  but  if  the  coaling  process  for  some  reason  or 
other  gets  out  of  order  and  fails,  then  the  loss  will  of 
course  be  greater.  It  has  already  been  stated,  there- 
fore, that  on  new,  unreliable  hearths  the  first  metiers 
should  be  made  smaller  than  usual.  On  old,  good  hearths 
the  meiler s  are  regarded  as  having  the  proper  size  when 


HAND-BOOK   FOR   CHARCOAL    BURNERS.  155 

they  measure  90  to  100  feet  in  circumference  at  middle  of 
the  billets.  Still  the  circumference  of  the  meiler  must  be 
regulated  somewhat  by  the  length  of  the  billets ;  other- 
wise it  might  become  so  steep  that  it  would  be  difficult  to 
make  the  dust  stay  on,  or  to  avoid  this  inconvenience  the 
lower  ends  of  the  billets  would  have  to  be  put  pretty  far 
out  from  each  other,  which  is  also  injurious.  If  we,  on 
the  other  hand,  use  short  billets,  raised  in  two  or  three 
tiers  above  each  other,  then  it  is  far  easier  to  give  the  de- 
sired form  and  in  this  way  we  may  make  the  meiler  much 
smaller  in  circumference  and  still  have  it  slope  as  much 
as  is  needed  to  keep  the  dust  in  its  place. 

The  usual  size  of  the  lying  meiler  has  already  been 
stated,  but  it  is  also  true  of  these  that  they  should  be 
made  considerably  smaller,  when  the  hearths  are  new  and 
unreliable. 

Economy  in  coaling  requires  that  the  meilers  should  be 
built  near  together  so  far  as  possible.  One  collier  can  watch 
at  least  two  standing  meilers  or  three  lying  meilers  at  the 
same  time. 

The  Cubic  Measurement  of  Meilers. 

In  calculating  the  cubic  contents  of  a  meiler,  we  should 
distinguish  carefully  between  the  actual  and  apparent 
quantity  of  solid  wood.  The  actual  quantity  of  wood, 
which  can  be  estimated  accurately  only  by  calculating  the 
cubic  contents  of  each  billet  separately,  means  the  real 
amount  of  wood  in  the  meiler,  after  subtracting  all  the 
vacuums  between  the  separate  billets.  The  apparent 


156  HAND-BOOK   FOR   CHARCOAL   BURNERS. 

quantity  of  wood  is  found  by  making  an  allowance  for 
the  vacuums.  The  latter  method  of  estimating  the  cubic- 
con  lents  of  wood  in  a  meiler  is  the  most  common,  and  is 
sufficiently  reliable  for  estimating  the  result  of  coaling,  if 
we  at  the  same  time  take  into  consideration  the  kind 
of  meiler  and  the  quality  of  wood.  In  using  medium- 
sized  straight  billets,  we  may  generally  assume  that  the 
actual  quantity  of  wood  is  in  the  lying  meiler  67  per  cent., 
and  in  the  standing  meiler  61  per  cent,  of  the  apparent 
quantity;  hence  the  vacuums  constitute  33  per  cent,  in 
the  former,  and  39  per  cent,  in  the  latter.  But  in  meilers 
made  of  crooked  wood,  or  of  limbs,  waste  wood,  etc.,  the 
vacuums  will  be  much  larger  in  proportion,  so  that  they 
may  amount  to  even  50  per  cent,  of  the  apparent  quan- 
tity of  wood. 

If  the  wood  which  is  to  be  used  is  corded  beforehand, 
it  is  easy  to  estimate  from  the  cubic  contents  of  the  corded 
heaps  what  the  apparent  quantity  of  wood  in  the  meiler 
will  be,  but  it  is  more  common  to  measure  the  meiler 
itself  and  calculate  its  volume  from  the  measurements 
taken. 

Calculation   of  the  Apparent  Quantity  of  Wood  in  a 
Standing  Meiler. 

The  standing  meiler  may  be  estimated  either  as  a  cylin- 
der or  "as  the  frustum  of  a  cone.  In  the  former  case  the 
circ«  inference  of  the  meiler  is  measured  in  the  middle  of 
the  billets.  If  its  circumference  measured  in  feet  is  call- 
ed C,  and  the  height  of  the  meiler  without  the  covering 


HAND-BOOK   FOR   CHARCOAL    BURNERS.  157 

H,  then  we  get  the  volume  of  the  billets  in  cubic  feet  by 

IT    /""12 

the  following  formula  :  —  . 

l^.obo 

If,  for  instance,  the  circumference  of  the  meiler  were  87 
feet  and  its  height  9  feet,  the  calculation  will  be  as  follows  : 
9  x  87a=68,121,  which  divided  by  12.566  =  5,421.  To  this 
result  we  must  afterwards  add  the  cubic  contents  of  the 
covering,  which  is  found  either  by  calculating  it  in  the 
manner  below  as  the  frustum  of  a  cone,  or  by  cording  the 
wood  before  putting  it  into  the  covering.  The  cubic  con- 
tents of  the  corded  heap  are  easily  found,  since  if  it  is  a 
feet  long,  ~b  feet  wide,  and  c  feet  high,  then  it  will  contain 
a  times  b  times  c  cubic  feet  of  apparent  quantity  of  wood. 
If  the  billets  are  raised  in  2  or  3  tiers,  then  each  tier 
should  be  calculated  as  a  cylinder  by  itself. 

But  as  the  billets  in  a  standing  meiler  have  the  form  not 
of  a  cylinder,  but  of  the  frustum  of  a  cone,  so  a  more  ac- 
curate result  is  obtained  by  calculating  the  contents  as  a 
frustum,  which  will  give  a  somewhat  larger  result.  This 

is  done  bv  the  following  formula  :          —  .  (Ca  +  C.c  +  c.c,  in 

o7.o98 

which  C  indicates  the  circumference  of  the  meiler  at  the 
foot,  c  at  the  brow,  and  H  its  height  from  the  foot  to  the 
brow. 

If,  for  instance,  the  height  of  the  meiler,  excepting  the 
covering,  were  10  feet,  the  lower  circumference  94  feet,  and 

the  upper  circumference  65  feet,  then  we  get  ono   (  94a 


+  94  x  65  -f  65  x  65)^0.265  (8,836  +  6,110  +  4,225)^5,080 
cubic  feet. 


158  HAND-BOOK   FOR   CHARCOAL   BURNERS. 

To  measure  the  circumference  at  the  brow  is  somewhat 
difficult,  but  it  is  only  necessary  to  measure  the  diameter 
of  the  meiler  at  that  place ;  for  if  this  diameter  is  d  feet 
the  upper  circumference  is  found  by  multiplying  d  by 
3.1416. 

If  the  contents  of  the  same  were  calculated  as  a  cylinder 

then,  as  the  circumference  at  the  middle  is  —     =76.5, 

, ,  ,     10x79.5x79.5     K  A__     .  .    -    t  „ 
the  result  would  be    -  -  =5,020  cubic  feet,  from 

1.2.OOO 

which  we  see  that,  whichever  method  of  calcuation  is 
used,  the  result  will  be  nearly  the  same. 

We  must  also  now  observe  that  when  the  billets  below 
the  brow  are  raised  in  several  tiers,  the  cubic  contents  of 
each  tier  should  be  calculated  separately,  and  that  the 
cubic  contents  of  the  covering  wood  should  be  added  to 
that  of  the  rest. 

According  to  these  rules  we  have  added  as  an  appendix 
two  tables,  which  show  the  apparent  quantity  of  wood,  ex- 
cepting the  covering,  in  standing  meilers  of  different  di- 
ameters and  heights.  In  Table  1  the  meilers  are  consid- 
ered as  cylinders,  and  in  Table  2  as  frustums  of  a  cone. 

In  Yermland  the  wood,  which  is  put  into  a  meiler  10 
feet  high  below  the  brow,  as  is  the  common  usage  there, 
and  10  fathoms  (the  fathom  is  6.5  feet)  in  circumference 
at  the  middle,  is  called  a  "  langved  "  (a  measure  of  wood). 
If  the  circumference  is  12  fathoms  the  meiler  is  estimated 
to  contain  1^- langveds  ;  14  fathoms  2  langveds ;  15  fathoms 
2£  langveds,  etc.  This  method  of  calculating  the  contents 


HAND-BOOK  FOR  CHARCOAL  BURNERS.        159 

of  the  meiler,  of  itself  easy  and  comprehensible,  is  so  firm- 
ly fixed  in  the  minds  of  the  common  people  that  when  a 
certain  number  of  langveds  is  named  in  regard  to  the  meiler , 
its  hearth,  etc.,  the  people  know  immediately  the  meaning 
of  the  expression.  Still  this  method  is  not  accurate  enough 
when  the  circumference  of  the  meiler  exceeds  14  fathoms. 
But  for  every  separate  case  it  is  quite  easy  to  calculate  in 
figures  how  many  langveds  are  contained  in  metiers  of 
different  peripheries,  upon  the  Yermland  supposition  that 
a  meiler  10  fathoms  (65  feet)  in  circumference  contains 
one  langved.  This  is,  by  finding  the  circumference  at  the 
middle  expressed  in  fathoms,  square  this  and  divide  by 
100.  The  result  will  be  that 

9.  fathoms  circumference  make  0.81  langveds. 

10.  "  "  "  1.  "        '"  . 

11.  "  "  "  1.21  " 

12.  "  "  "  1.44  « 
12.3  "  "  "  1.51  " 

13.  "  "  "  1.69  " 

14.  "  "  "  1.96  " 
14.5  "  "  "  2.10  « 

15.  "  "  "      2.25        " 
and  so  on. 

Calculation  of  the  Apparent  Quantity  of  Wood  in  a 
Lying  Meiler. 

The  forms  of  the  lying  meilers  are  so  many  that  no  ac- 
curate and  complete  tables  can  well  be  given  for  estimating 
their  cubic  contents.  Furthermore,  the  length  of  the  billets 


160 


HAND-BOOK   FOR   CHARCOAL   BURNERS. 


makes  it  inconvenient  to  cord  them.  If  this  could  be  done 
the  cubic  contents  conld  be  easily  estimated.  We  therefore 
must,  in  every  separate  case,  first  measure  the  meiler,  and 
then  from  the  measurements  taken  calculate  the  cubic  con- 
tents of  wood,  which  is  done  by  first  calculating  the  exte- 
rior surface  of  one  of  the  gables  in  square  feet,  and  after- 


6 


FIG.  10. 


ward  multiply  the  number  obtained  by  the  length  of  the 
billets  expressed  in  feet ;  the  product  will  then  be  the  ap- 
parent quantity  of  wood  expressed  in  cubic  feet.  For  cal- 
culating the  surface  of  the  gables  we  may  generally  assume 
the  form  represented  in  Fig.  10  ;  that  is  to  say,  that  the  roof 
has  a  plane  slope  from  the  covering  to  both  sides,  and  that 
the  meiler  is  perpendicular  both  at  the  foot  and  rear  wall. 
The  measuring  is  done  in  the  manner  exhibited  in  Fig.  10, 
and  the  calculation,  with  the  measurements  obtained,  is 
done  as  follows: 


HAND-BOOK   FOR    CHARCOAL    BURNERS. 


161 


5  +  13  =  18,  half  of  which  9  x  19=171  sq.  ft. 
11  +  13=24,    "     "       "      12x6=  72    «     « 
The  surface  of  the  gables  =~~         243    "     " 

If  the  billets  are  20  feet  long,  then  the  cubic  contents  of 
the  meil&r  will  be  243  x  20=4,860  cubic  feet. 

The  error  which  is  made  in  this  method  of  calculating 
the  surface  of  the  gable  by  assuming  that  the  meiler  is  at 
right  angle  with  the  hearth,  both  at  the  rear  and  foot,  we 
need  not  take  into  consideration,  provided  the  slope  of  the 
walls  inward  is  not  considerable,  especially  as  this  error  is 
counterbalanced  by  the  other  error  of  considering  the  roof 
as  having  from  the  covering  to  the  rear  wall  not  a  convex 
but  a  plane  surface.  But  if  there  is  considerable  slope  in- 
ward at  the  foot  and  rear  of  the  meiler,  we  may  resort  to 
dividing  the  gable  wall  into  four  parts,  as  is  shown  in  Fig. 
11,  and  the  square  contents  of  the  gable  surface  will  then 
be: 


a 


FIG.  11. 


axe     be  +  f      f+g     d  xg 

2  2  2T     2    ' 


162  HAND-BOOK   FOR   CHARCOAL    BURNERS. 

In  calculating  the  actual  or  apparent  quantity  of  wood, 
we  must  not  of  course  forget  to  include,  the  filling  wood. 

The  Charcoal  Product. 

In  order  to  estimate  properly  the  result  of  coaling,  it  is 
necessary,  as  the  reader  already  knows,  to  give  due  atten- 
tion to  all  kinds  of  circumstances,  which  frequently  oper- 
ate materially  against  the  regular  progress  of  the  coaling, 
and  make  it  impossible  to  get  an  amount  of  charcoal 
directly  proportional  to  the  amount  of  wood.  No  one 
must  think,  even  if  the  hearth  is  dry  and  free  from 
draught,  the  wood  of  good  quality,  and  the  collier  does  his 
work  properly  from  beginning  to  end,  that  about  the  same 
amount  of  charcoal  in  volume  always  can  be  produced  by 
any  certain  volume  of  solid  wood.  It  has  been  shown 
heretofore,  that  charcoal  made  from  spruce  contains  more 
cracks  and  openings  than  that  made  from  pine,  and  it 
follows  from  this  that  the  former  is  more  voluminous  and 
that,  other  things  being  equal,  spruce  apparently  produces 
more  charcoal  than  pine.  It  has  also  already  been  stated 
that  small  wood  cracks  less  to  pieces  in  coaling  than  large, 
and  to  this  we  must  add  that  small  charcoal  leaves  less 
vacuum  in  the  measure  than  large  charcoal,  which  explain 
two  things.  It  explains  our  experience,  that  charcoal  made 
of  young  timber,  as  well  as  slabs,  limbs,  etc.,  is,  as  it  is  said, 
stronger,  that  is  to  say,  contains  in  the  same  volume  more 
solid  charcoal,  than  that  made  of  large,  mature  stems;  and 
also  that,  as  a  general  rule,  the  smaller  the  billets  are, 
the  greater  will  be  the  product  of  charcoal,  since  this 


HAND-BOOK  FOR  CHARCOAL  BURNERS.        163 

is  estimated  usually,  or  we  may  say  always,  by  the  volume 
of  the  apparent  quantity  of  charcoal. 

For  measuring  charcoal,  the  measure  which  is  called  a 
last,  and  which  contains  75.6  cubic  feet,  is  the  most  com- 
mon. For  one  last  of  charcoal  there  is  consumed,  even  un- 
der the  most  favorable  circumstances,  not  less  than  55  cubic 
feet  of  solid  spruce  wood  or  60  cubic  feet  of  solid  pine,  and 
we  may  say  generally  that  the  coaling  is  a  success  when 
for  one  last  of  charcoal  there  has  not  been  consumed  more 
than  60  to  75  cubic  feet  of  solid  wood,  of  course  including 
the  filling  wood.  Even  with  90  cubic  feet  of  solid  wood 
for  one  last  of  charcoal  the  coaling  is  fair,  but  with  more 
than  90  cubic  feet  the  coaling  is  poor. 

Closing  Remarks. 

We  may  safely  say  that  although  coaling,  in  order  to  be 
done  properly  and  economically,  requires  not  only  much 
practice,  but  also  a  certain  amount  of  knowledge,  still  no 
other  branch  of  industry  of  corresponding  importance  in 
our  country  has  been  so  neglected.  For  although,  espe- 
cially recently,  many  owners  of  timber,  who  have  learned 
to  appreciate  an  economical  use  of  it  in  general,  have 
tried,  and  even  partially  succeeded,  with  the  assistance  of 
men  educated  in  the  profession,  to  introduce  among  other 
things  a  more  rational  method  of  coaling,  still  these 
efforts  form  as  yet  only  a  few  solitary  exceptions  from 
the  general  rule.  Wherefore  an  immense  quantity  of 
wood  is  annually  consumed  to  no  purpose;  besides  the 
charcoal  which  is  produced  is  generally  poorer  and  more 


164  HAND-BOOK   FOR    CHARCOAL   BURNERS. 

expensive  than  it  would  be  if  the  coaling,  and  everything 
connected  with  it,  received  at  least  a  fair  amount  of  atten- 
tion. 

From  the  small  land-owners  who  make  charcoal,  and 
who  almost  everywhere  regard  the  work  of  coaling  as  a 
subsidiary  support  during  the  seasons  of  the  year  when 
agriculture  does  not  furnish  employment  to  them  and  their 
servants,  no  reform  can  be  expected,  at  least  not  before, 
by  the  power  of  example,  there  is  forced  upon  them  a 
conviction  of  the  great  advantages  with  which  an  econo- 
mical use  of  timber  and  a  scientific  method  of  coaling 
will  reward  them.  It  is  from  the  large  owners  of  timber 
the  impulse  to  a  general  reform  must  come,  and  they  are 
the  very  ones  who  will  reap  the  greatest  benefit  and  profit 
from  proper  economy  in  timber  and  coaling  interests. 

The  first  condition  for  such  a  reform  is  that,  just  as 
men  with  theoretical  knowledge  and  practical  ability  are 
employed  in  agriculture,  machine-shops,  and  other  branches 
of  industry,  so  there  should  be  employed  correspondingly 
well-educated  and  able  men  to  take  care  of  our  timber, 
and  men  who  are  not  afraid  to  soil  their  fingers  and  spend 
their  time  at  the  meiler. 

Another  important  condition  is  that  coaling  should  be 
separated  from  all  other  factories  and  from  agricultural 
pursuits.  On  the  contrary,  we  find,  as  a  rule,  that  the 
colliers,  even  where  they  are  not  peasants  or  their  servants, 
are  occupied  too  much  with  other  work,  and  hence  they 
neglect  the  coaling,  which,  as  the  reader  knows,  requires 
the  greatest  care  and  attention.  Of  course  there  are  ex- 


HAND-BOOK   FOR    CHARCOAL    BURNERS.  1C5 

ceptions,  but  the  skilled  colliers  that  are  scattered  here 
and  there  have  scarcely  any  influence  upon  fellow-crafts- 
men. The  discoveries  and  experiences  which  they  have 
made  usually  die  with  them,  and  their  successors  have  to 
begin  anew  again,  we  may  say,  without  any  intelligent 
supervision  or  guidance  at  all. 

If  we  want  a  better  method  of  coaling  firmly  rooted, 
men  should  be  selected  as  colliers  who  have  good  com- 
mon sense  and  have  talent  for  this  kind  of  work. 

In  the  next  place,  we  should  try  to  give  them  an  oppor- 
tunity to  give  so  far  as  possible  their  whole  time  to  coaling, 
and  encourage  them  to  constant  progress  in  this  employ- 
ment, which  of  itself  is  so  unattractive. 

If  we  succeed  in  educating  a  skilled  industrious  class  of 
colliers,  who  are  devoted  to  their  work,  it  will  make  com- 
paratively little  difference  which  method  of  coaling  we 
adopt. 


166 


HAND-BOOK   FOR   CHARCOAL    BURNERS. 


TABLE   No.    1, 

The  Cubic  Contents  of  Standing  Meilers  calculated  as 
Cylinders. 


65 
66 
67 

68 
69 
70 
71 
72 
73 
74 
75 
76 
77 
78 
79 
80 
81 
82 
83 
84 
85 
86 
87 


Cubic  feet  of  apparent  quantity  of 
wood  at  the  height  of 


3,119 


3,300 


3,486 


2,690  2,858  3,026  3,194  3,362 
2,773|2,946  3,120  3,293  3,466 
2,858)3,036  3,215  3,393  3,572 
2,944|3,128  3,312  3,496  3,679 
3,03113,220  3,410  3,599  3,788 


3,209  3,410  3,610  3,81 1  4,011 


3,393  3,605  3,817  4,029  4,241 


3,314  3,509  3,704  3,899 


3,5063,7133,9194.125 


3,704  3,922  4,140  4,358 


,          ,          ,         ,          , 
3,58113,805  4,029  4,253  4,476 
3,677J3,907  4,137J4,36(J  4,596 
3,774'4,010'4,246  4,482  4,718 
3,873'4,115  4,357  4,599  4,841 
3,973!4,221  4,470  4,718  4,9(56 
4,074'4,329  4.584  4.838  5,093 
4,177  4,438  4,699  4,960  5.221 
,281  4,548  4,816  5,083  5,351 
,386  4,660  4,934  5,208  5,482 
,492  4,773  5,053  5,334  5,615 
,600  4,887  5,174  5,462  5,749 
,708  5,003  5,297  5,591  5,886 
4,819  5,120  5,421  5,722  6,023 


90 

91 

92 

93 

94 

95 

96 

97 

98 

99 

100 

101 

102 

103 

104 

105 

106 

107 

108 

109 

110 


lubic  feet  of  apparent  quantity  of 
wood  at  the  height  of 


5,157 


4,930  5,238 
5,043  5,358 


5,479  5,801 


5,272  5,601  5.931  6,2606,590 
5,3885,7256,0626,3996,735 
5,506  5,850j6, 194  8,5386,888 
5,625!5,977,6,328  6,68()|7,03l 
5,745'6,105'6,464  6,823  7,183 
5,867^,234  6,600  6,977  7,334 


5,5465,8546,162 
5,988  6,303 
6,123  6,446 


5,9906,3646,7397,113 
6,1146.4966,8787,260 


6,2396.6297,0197,409 
6,366  6,764  7,162  7,560  7,958 
6,494  6,900  7,306  7,712  8,118 


6,623  7,037 
8,7547,176 


7,451 

r,598 


8,886  7,316  7,746  8,1, 
7,019  7,457  7.896  8,885  8,778 
7,153,7,600,8,047  8,49418,941 
7,289  7,744  8,200  8,655  9,111 
7,42517,890  8,354  8,818  9,282 
7,564!8,0:}6  8,509  8,982  9,454 
7,703!8,184  8,666  9,147:9,629 


7,487 
7,643 
'99 


7,865  8,279 
8,020  8,442 
8,607 


HAND-BOOK   FOR   CHARCOAL   BURNERS. 


167 


TABLE    No.    2. 

The  Cubic  Contents  of  Standing  Meilers  calculated  as 
Frusta  of  Cones. 


CUBIC   FEET   OF   APPARENT   QUANTITY    OF   WOOD   AT  A   HEIGHT 
OF    8    FEET. 


1  . 

1, 

•1 

| 

£ 

=2   . 

o 

S 

L 

U) 

1 

o 

!H 

jj 

1  . 

I 

11 

s  "S 

g 

c  • 

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flj 

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£  lip 

1 
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3,000 

80 

55 

2,931 

83 

45 

2,682 

H 

30 

1,860 

u 

65 

3,244 

u 

60 

3,137 

50 

2,870 

1  1 

35 

2009 

78 

25 

1,836 

li 

65 

3,355 

55 

3,070 

u 

40 

2.168 

u 

30 

1,977 

u 

70 

3,583 

60 

3,279 

u 

45 

2,337 

u 

35 

2,128 

81 

30 

2,097 

65 

3,500 

u 

50 

2,518 

ti 

40 

2,290 

u 

35 

2,252 

70 

3,731 

u 

55 

2,708 

u 

45 

2,463 

u 

40 

2,417 

84 

30 

2,221 

II 

60 

2,910 

H 

50 

2,647 

" 

45 

2,593 

35 

2,379 

41 

65 

3,122 

li 

55 

2,841 

u 

50 

2,780 

40 

2,547 

76 

25 

1,760 

M 

60 

3,045 

u 

55 

2,977 

45 

2,727 

(i 

30 

1.899 

u 

65 

3,260 

(1 

60 

3,184 

50 

2,916 

u 

35 

2,050 

79 

25 

1,874 

u 

65 

3,403 

55 

3.119 

u 

40 

2,208 

" 

30 

2,016 

(i 

70 

3,632 

60 

3,328 

H 

45 

2,379 

u 

35 

2,169 

82 

80 

2,139 

65 

3,549 

it 

50 

2,560 

(4 

40 

2,333 

u 

35 

2,294 

70 

3,781 

U 

55 

2,752 

u 

45 

2,506 

II 

40 

2,460 

80 

30 

2,263 

(| 

60 

2,954 

<  ( 

50 

2.690 

u 

45 

2,637 

35 

2,422 

U 

65 

3,167 

K 

55 

2,886 

t< 

50 

2,825 

40 

2,592 

77 

25 

1,798 

" 

60 

3,091 

u 

55 

3,023 

45 

2,772 

u 

30 

1,937 

U 

65 

3,307 

u 

60 

3,232 

50 

2,963 

H 

35 

2,088 

80 

30 

2,056 

u 

65 

3,451 

55 

3,164 

U 

40 

2,249 

ct 

35 

2,210 

u 

70 

3,681 

60 

3,376 

u 

45 

2,421 

t< 

40 

2,374 

83 

30 

2,179 

65 

3,599 

u 

50 

2,603 

u 

4.1J 

2,549 

It 

35 

2,336 

70 

3,832 

ri 

55 

2,796 

14 

50 

2,738 

u 

40 

2,504 

86 

30 

2,306 

168 


HAND-BOOK   FOR   CHARCOAL   BURNERS. 


CUBIC   FEET    OF   APPARENT   QUANTITY   OF   WOOD  AT  A  HEIGHT 

OF  8  FEET. —  Continued. 


1  . 

1  , 

i 

1 

1  - 

1 

J>  - 

L 

•1 

1  , 

6 

I 

Il 

II 

g 

11 

li 

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gl 

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p 

8 

3 

p 

6 

1 

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1 

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P 

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86 

35 

2,466 

88 

60 

3,524 

91 

40 

2,866 

93 

60 

3,780 

u 

40 

2,639 

u 

65 

3,750 

»« 

45 

3,053 

14 

65 

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HAND-BOOK   FOB   CHARCOAL   BURNERS. 


109 


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171 


CUBIC   FEET   OF   APPARENT   QUANTITY    OF  WOOD   AT  A   HEIGHT 

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HAND-BOOK   FOR   CHARCOAL    BURNERS.  173 


APPENDIX. 


*  NOTE   I. 

Lignin. 

LIGNIN  constitutes  the  fundamental  material  of  the  struc- 
ture of  plants  ;  it  is  employed  in  the  organization  of  cells 
and  vessels  of  all  kinds,  and  forms  a  large  proportion  of 
the  solid  parts  of  every  vegetable.  It  must  not  be  con- 
founded with  ligneous  or  woody  tissue,  which  is  in  reality 
cellulose,  with  other  substances  superadded  which  encrust 
the  walls  of  the  original  membranous  cells  and  confer 
stiffness  and  inflexibility.  Thus  woody  tissue,  even  when 
freed  as  much  as  possible  from  coloring  matter  and  resin 
by  repeated  boiling  with  water  and  alcohol,  yields  on  an- 
alysis a  result  indicating  an  excess  of  hydrogen  above  that 
required  to  form  water  with  the  oxygen,  besides  traces  of 
nitrogen.  Pure  cellulose,  on  the  other  hand,  is  a  tertiary 
compound  of  carbon  and  the  elements  of  water,  closely 
allied  in  composition  to  starch,  if  not  actually  isomeric 
with  that  substance.  The  properties  of  lignin  maybe  con- 
veniently studied  in  fine  linen  and  cotton,  which  are  al- 

*  Fowne's  Chemistry,  page  359. 


174  HAND-BOOK   FOR   CHAKCOAL    BURNERS. 

most  entirely  composed  of  the  body  in  question,  tlie  asso- 
ciated vegetable  principles  having  been  removed  or  de- 
stroyed by  the  variety  of  treatment  to  which  the  fibre  has 
been  subjected.  Pure  lignin  is  tasteless,  insoluble  in  water 
and  alcohol,  and  absolutely  innutritious;  it  is  not  sensibly 
affected  by  boiling  water,  unless  it  happens  to  have  been 
derived  from  a  soft  or  imperfectly  developed  portion  of 
the  plant,  in  which  case  it  is  disintegrated  and  rendered 
pulpy.  Dilute  acids  and  alkalies  exert  but  little  action  on 
lignin,  even  at  a  boiling  temperature  ;  strong  oil  of  vitriol 
converts  it,  in  the  cold,  into  a  nearly  colorless,  adhesive 
substance,  which  dissolves  in  water  and  presents  the  char- 
acter of  dextrin.  This  curious  and  interesting  experiment 
may  be  conveniently  made  by  very  slowly  adding  concen- 
trated sulphuric  acid  to  half  its  weight  of  lint,  or  linen 
cut  into  small  shreds,  taking  care  to  avoid  any  rise  in  tem- 
perature, which  would  be  attended  with  charring  or  black- 
ening. The  mixing  is  completed  by  trituration  in  a  mortar, 
and  the  whole  left  to  stand  for  a  few  hours,  after  which  it 
is  rubbed  up  with  water,  and  wanned,  and  filtered  from  a 
little  insoluble  matter.  The  solution  may  then  be  neutralized 
with  chalk  and  again  filtered.  The  gummy  liquid  retains 
lime  partly  in  the  state  of  sulphate,  and  partly  in  combi- 
nation with  a  peculiar  acid,  composed  of  the  elements  of 
sulphuric  in  union  with  those  of  the  lignin,  to  which  the 
name  sulpholignic  acid  is  given.  If  the  liquid,  previous 
to  neutralization,  be  boiled  during  three  or  four  hours  and 
the  water  replaced  as  it  evaporates,  the  dextrin  becomes 
entirely  changed  to  grape  sugar.  Linen  rags  may,  by  these 


HAND-BOOK   FOR   CHARCOAL   BURNERS.  175 

means,  be  made  to  furnish  more  than  their  own  weight  of 
that  substance.     Lignin  is  not  colored  by  iodine. 

NOTE   II. 

Charring  foliferous  and  coniferous  trees. 

There  is  no  important  distinction  between  the  treatment 
of  foliferous  and  coniferous  trees,  in  the  manufacture  of 
charcoal.  Whatever  differences  there  may  be  are  men- 
tioned in  the  text. 

NOTE   III. 

Sour  wood  and  hearth. 

There  is  a  condition  of  wood  in  which  the  sap  which  it 
contains  begins  to  ferment,  or  turn  acetic,  before  the 
woody  texture  is  attacked,  and  before  we  can  say  it  has 
begun  to  decay  or  rot ;  wood  in  this  condition  is  said  to 
be  sour.  The  acetic  acid  of  the  wood  makes  the  hearth 
sour. 

NOTE   IV. 

Last  as  a  measure. 

A  last  is  a  measure  of  eighteen  barrels,  or  75.6  cubic 
feet. 

NOTE  v. 

Charring  in  ovens  or  kilns. 
In  order  *  to  avoid  keeping  large  stores  of  charcoal,  and 

*  A  Practical  Treatise  on  Metallurgy,  by  Crookes  and  Rohrig,  page 
367. 


176  HAND-BOOK   FOR   CHARCOAL    BURNERS. 

to  obtain  it  dry  and  fresh,  to  save  labor  in  particular  cases, 
and  to  be  less  subject  to  the  faults  of  inferior  workmen, 
the  charring  in  ovens  or  kilns  is  resorted  to. 

Generally  speaking,  the  advantages  of  ovens  over  heaps 
or  pits  are  not  so  great  as  is  often  supposed,  and,  as  a  rule, 
we  may  assert  that  no  charcoal  made  under  an  immovable 
covering  is  so  strong  as  that  made  under  a  movable  one. 
The  only  real  advantage  of  the  oven  arises  from  its  being 
less  subject  to  the  changes  of  the  atmosphere  than  the 
pit.  The  best  kind  of  char  oven,  and  that  which  is  most 
generally  in  use  in  America,  is  of  a  long,  prismatic  form  ; 
the  floor  and  rough  walls  of  the  oven  are  of  common  red 
brick ;  the  interior  of  the  side  walls  and  the  arched  roof 
are  lined  with  fire-brick.  Such  an  oven  is  40  feet  long, 
15  feet  wide,  and  15  feet  high,  in  the  clear,  and  will  con- 
tain about  sixty  cords  of  wood. 

The  oven  is  bound  with  wood  and  covered  with  a  roof, 
which  is  a  necessary  appendage,  as  it  protects  the  walls 
against  moisture,  which  is  particularly  hurtful  to  the  arch 
and  consequently  to  the  coal.  The  floor  is  well  paved  with 
hard,  common  bricks  set  edgewise  ;  below  these  another 
layer  of  bricks  or  stones  is  laid  upon  a  plank  floor,  which 
rests  upon  the  cross  timbers  or  binders.  The  mode  of 
binding  requires  no  further  explanation  ;  it  may  be  added, 
however,  that  it  is  necessary  to  use  young  and  sound  tim- 
ber for  this  purpose.  The  bricks  are  laid  in  fire-clay 
mortar,  in  preference  to  lime  mortar,  because  the  latter  is 
soon  destroyed  by  the  acetic  acid  which  is  liberated  by 
the  wood.  This  clay  mortar  ought  not  to  be  too  fat,  and 


HAND-BOOK   FOK   CHARCOAL   BURNERS.  177 

it  is  advisable  to  use  a  little  salt  in  it ;  this  causes  it  to  dry 
harder  and  bind  more  strongly.  In  laying  the  bricks  par- 
ticular care  must  be  taken  to  fill  the  joints  perfectly  with 
mortar,  that  no  leakage  may  take  place  through  the  walls, 
which,  for  better  security,  may  be  painted  on  the  outside 
with  a  mixture  of  coal  tar  and  clay.  This  forms  an  ex- 
tremely hard  and  strong  cover,  which  is  not  at  all  liable 
to  break.  The  clay  is  dissolved  in  water  and  put  first 
over  the  brick  wall,  like  a  wash ;  the  tar  is  then  painted 
on  before  it  has  become  perfectly  dry. 

In  order  to  secure  strength  and  close  joints,  the  walls 
must  be  at  least  14  inches  thick,  consisting  of  a  lining  of 
fire-brick  5  inches  in  width,  and  red  brick  9  inches.  Both 
the  lining  and  rough  wall  must  be  well  bound  together  by 
occasional  binders,  which  unite  the  red  and  the  fire-brick. 
The  arch  may  be  of  5-inch  fire-brick;  but  as  the  space  is 
wide,  there  is  no  harm  done  in  making  a  10-inch  roof. 
Many  kilns  are  built  of  red  brick  only ;  to  this  there  is  no 
objection,  they  answer  equally  as  well  as  if  lined  with  fire- 
brick ;  but  in  this  case,  the  common  bricks  ought  to  be 
made  of  a  kind  of  loam  which  will  stand  fire  well.  If  this 
loam  contains  too  much  iron  or  lime,  the  bricks  of  the  roof 
will  soon  shrink  and  drop. 

It  is,  therefore,  necessary  to  test  the  red  bricks  in  a  strong 
fire  before  a  kiln  is  built  of  them,  at  least  those  used  for 
the  lining  and  the  roof  ;  if  they  resist  a  high  red  heat  with- 
out melting,  they  may  be  considered  good  for  this  purpose. 
When  a  little  more  expense  is  no  consideration,  it  is  a  good 
plan  to  increase  the  strength  of  the  side  walls  by  bracing 


378  HAND-BOOK    FOR    CHARCOAL    BURNERS. 

them  with  pillars.  At  each  end  there  is  an  iron  door,  6 
feet  wide,  and  8  feet  high,  so  that  a  railroad  car  can  be 
run  into  the  oven,  loaded  with  wood,  or  to  take  off  charcoal. 
All  the  kilns  in  use  resemble  the  above  more  or  less ;  in 
some  cases  the  roof  is  less  steep,  to  gain  room ;  in  others 
the  binders  are  made  of  cast-iron  uprights,  and  wrought- 
iron  cross  girders.  In  some,  the  gases  are  drawn  off  by  a 
series  of  vents  in  the  top  of  the  roof ;  in  others,  by  vents 
at  both  ends ;  when  this  is  the  case,  the  vent-holes  are 
provided  with  iron  doors.  In  all  cases,  a  series  of  draught 
holes  is  provided  quite  round  the  foot  of  the  kiln,  and  by 
stopping  one,  and  opening  another,  the  access  of  air,  and 
consequently  the  fire,  is  regulated.  These  apertures  are  of 
the  size  of  a  brick  10  inches  by  2^  in  height,  so  that  a  brick 
may  fill  one. 

The  operation  of  charring  in  these  kilns  is  extremely 
simple.  The  wood  is  laid  flat  on  the  floor  and  piled  up  to 
the  roof.  It  may  also  be  set  upright,  but  as  this  is  more 
laborious  it  is  not  generally  done  ;  still  there  is  no  doubt 
that  the  coal  is  stronger  from  the  billets  which  are  standing 
than  from  those  which  are  laid  flat.  The  fire  is  applied  in 
various  ways ;  some  prefer  putting  it  at  the  top,  in  the 
middle  of  the  arch,  and  drawing  it  gently  downwards ; 
others  form  a  channel  of  brands,  dry  chips,  or  charcoal 
through  the  middle  of  the  floor,  and  apply  fire  at  both  ends  ; 
others,  again,  ignite  the  wood  at  the  draught-holes  around 
the  foot  of  the  oven.  Of  all  these  plans  the  latter  is  the 
most  objectionable,  for  it  necessarily  causes  a  waste  of 
wood,  and  makes  weak  coal.  With  a  channel  through  the 


HAND-BOOK    FOR   CHARCOAL   BURNERS.  179 

middle,  firing  at  both  ends  is  better,  but  the  best  plan  is 
firing  on  the  top,  particularly  in  the  wide  ovens.  In  all 
eases  the  wood  that  is  charred  ought  to  be  well  seasoned, 
for  wet  or  green  wood  yields  20  per  cent,  less  coal  than 
dry  ;  or,  in  case  seasoned  wood  cannot  be  had,  the  charring 
ought  to  be  conducted  with  extreme  slowness  ;  the  fire 
should  be  applied  at  the  top,  and  fed  by  coal  or 
brands. 

A  liberal  supply  of  fresh  air  should  be  allowed  to  pass 
through  the  interior. 

Charring  green  or  wet  wood  is  in  no  case  profitable,  and 
in  order  to  obtain  the  best  yield  and  greatest  amount  of 
coal,  the  wood,  as  it  is  delivered  at  the  yard,  should  be 
stored  under  cover  and  protection  against  the  rain.  One 
heat  may  be  performed  in  a  week,  so  that  an  oven  may  be 
reckoned  to  produce  from  1,200  to  1,500  bushels  of  coal  in 
that  time,  but  generally  two  or  three  weeks  are  occupied 
in  charging,  charring,  and  discharging  a  kiln.  It  is  not 
difficult  to  conduct  the  charring  in  these  ovens  when  the 
walls  are  perfectly  air-tight,  but  if  they  are  not  so  it  is 
rather  troublesome,  and  causes  considerable  loss  of  wood. 

When  the  watery  vapors  at  the  top  of  the  kiln  or  at 
the  vents  cease,  and  no  smoke  of  any  kind  issues,  but  a 
whitish  blue  gas  makes  its  appearance — which  is  often  the 
case  at  the  third  day  after  the  fire  is  applied,  although 
more  generally  on  the  fourth  or  fifth  day — the  vents  are 
stopped  up,  and  as  the  fire  becomes  visible  at  the  aper- 
tures near  the  base,  these  are  also  successively  stopped. 
When  satisfied  that  the  heat  has  spread  throughout  the  in- 


180 


HAND-BOOK    FOR    CHARCOAL    BURNERS. 


terior,  all  the  openings  are  well  stopped  by  bricks,  and 
secured  by  a  layer  of  fine  sand,  to  prevent  the  access  of  air. 


FIG.  12. 

Two,  or  at  the  most  four,  days  of  cooling  are  sufficient  to 
deaden  the  coal  so  far  as  to  make  it  ready  for  drawing. 

These  kilns  are  the  best  for  the  manufacture  of  metals. 

The  ovens  frequently  used  in  Sweden  are  from  25  to  30 
feet  wide,  17  or  18  feet  high,  and  of  equal  length  ;  they 
are  provided  with  a  pointed  arch,  2  feet  thick,  and  the 
side  walls  are  still  thicker.  These  furnaces  are  likewise 
constructed  for  collecting  the  products  of  combustion,  for 
which  purpose  they  answer  well ;  but,  on  the  other  hand, 
a  light  coal  is  produced  by  their  use. 

Chabeaussiere's  kiln,  for  making  wood  charcoal,  is  rep- 
resented in  Figs.  12  and  13.  Fig.  12  is  a  vertical  section, 
and  Fig.  13  a  half  bird's-eye  view  and  half  cross-section 
of  the  height  of  the  pit  bottom.  A  is  the  oven  ;  B,  vertical 
air-pipes  ;  c  c,  horizontal  flues  for  admitting  air  to  the  kiln ; 


HAND-BOOK   FOR   CHARCOAL    BURNERS. 


181 


d,  d,  small  pits  which  communicate  by  short  horizontal 
ones;  e,  e,  with  the  vertical  ones  ;  f,  the  sole  of  the  kiln,  a 
circle  of  brick-work,  upon  which  the  cover,  or  hood,  h,  re- 
poses ;  i,  a  pipe  which  leads  to  the  cistern,  k  ;  1,  the  pipe 
destined  for  carrying  off  the  gaseous  matter ;  in,  m,  holes 
in  the  iron  cover  or  lid. 

The  distribution  of  the  wood  is  like  that  in  the  horizon- 
tal meiler,  or  heaps ;  it  is  kindled  in  the  central  vertical 
canal  with  burning  fuel,  and  the  lid  is  covered  with  a  few 
inches  of  earth.  At  the  beginning  of  the  operation,  all  the 


FIG.  13. 


draught-flues  are  left  open,  but  they  are  successively  closed, 
as  occasion  requires.  In  eight  kilns  of  this  kind,  500  de- 
casteres  of  oak  wood  are  carbonized  (a  decastere  is  10  cu- 


182 


HAND-BOOK    FOR   CHARCOAL    BURNERS. 


a. 


bic  metres),  from  which  15,000  hectolitres  of  charcoal  are 
obtained  (a  hectolitre  is  100  litres),  equal  to  64,000  Ibs., 
French,  being  about  25  per  cent,  besides  tar  ;  3,000  velts  of 
wood  vinegar  (a  velt  is  7.61  litres)  of  from  2°  to  3°  Baume 
are  also  produced. 

Charcoal  obtained  by  the  action  of  a  rapid  fire  in  close 
vessels  is  not  so  solid  and  good  a  fuel  as  that  which  is 
made  in  the  old  way,  by  the  slow  calcination  of  pyramidal 
piles  covered  with  earth.  One  of  the 
most  economical  ovens  for  making 
wood  charcoal  is  that  invented  by  M. 
Foucauld,  which  he  calls  a  shroud  or 
abri.  To  construct  one  of  these,  30 
feet  in  diameter  at  the  base,  10  feet 
at  the  summit,  and  from  8  to  9  feet 
high,  he  forms  with  wood  2  inches 
square  a  frame  12  feet  long,  3  feet 
broad  at  one  end,  and  1  foot  the 
other. 

The  figures  14-17  will  explain  the 
construction. 

'he  uprights,  A,  B  and  C,  D,  of 
this  frame  are  furnished  with  three 
wooden  handles,  a,  a,  a,  and  a,  a,  a,  by  means  of  which 
they  can  be  joined  together,  by  passing  through  two  con- 
tiguous handles  a  wooden  fork,  the  frame  being  pre- 
viously provided  with  props,  as  shown  in  Fig.  12,  and 
covered  with  loam  mixed  with  grass.  A  flat  cover  of  10 
feet  diameter  made  of  planks  well  joined,  and  secured" 


FIG  15 


HAND-BOOK   FOR   CHARCOAL   BURNERS. 


183 


by  four  cross-oars  is  provided  with  two  trap-doors,  M,  N 
(Fig.  IT),  for  giving  egress  to  the  smoke  at  the  commence- 
ment of  the  operation ;  a  triangular  hole,  P,  cut  out  in  the 
cover,  receives  the  end  of  the  conduit,  q,  r,  s  (Figs.  16 
and  17),  of  wood  formed  of  three  deals  destined  to  con- 
vey the  gases  and  condensed  liquids  into  the  casks,  F,  G, 
II.  Lastly,  a  door,  T,. which  may  be  opened  and  shut  at 
pleasure,  permits  the  operator  to  inspect  the  state  of  the 
fire.  The  charcoal  produced  by  this  abri  has  been  found 
of  superior  quality. 


FIG.  .17. 

Where  it  is  thought  desirable  to  change  the  place  where 
the  abri  is  erected,  and  to  transport  it  to  a  store  of  new- 
felled  timber,  the  frame  is  taken  down,  after  beating  off 
the  clay  which  covers  it ;  the  joints  and  also  the  ends  of 
the  forks  which  fixed  the  frames  to  one  another  are  then 
cut  with  a  saw.  This  process  is  economical  in  use,  and 
simple  and  cheap  in  construction,  since  all  the  pieces  of 


184:  HAND-BOOK    FOR    CHARCOAL    BURNERS. 

the  apparatus  arc  easily  moved  about  and  may  be  readily 
mounted  in  the  forest. 

Mr.  J.  M.  White,  who  has  constructed  many  kilns  in  the 
northwest,  makes  them  as  follows : — 

The  foundation  is  composed  of  a  stone  wall  24  inches 
in  thickness  and  of  sufficient  height  to  bring  it  to  the 
working  floor  of  the  kiln,  which  in  most  cases,  when  dry 
ground  has  been  selected,  is  a  few  inches  above  the  level 
of  the  ground.  Upon  this  foundation  the  brick-work  is 
commenced,  its  shape  being  given  by  means  of  a  sweep 
placed  upon  a  staff  so  as  to  revolve  easily,  thus  giving  a 
true  circle  to  the  design.  This  wall  is  12  inches  in  thick- 
ness, and  contains  apertures  or  vents,  three  rows  of  which, 
placed  even  distances  apart,  encircle  the  kiln.  In  con- 
structing, it  is  the  better  plan  to  place  the  vents  so  each 
upper  vent  on  its  respective  circle  shall  come  between  the 
vents  below  or  in  the  circle  beneath  it. 

The  upper  course  or  circle  is  usually  from  three  to  four 
feet  from  the  working  floor,  and  the  lower  immediately 
upon  it,  the  third  circle  of  vents  being  equidistant  from 
upper  and  lower  ones.  At  the  elevation  of  8  feet  the 
thickness  of  the  wall  is  reduced  to  8  inches,  and  this 
thickness  continued  to  the  summit  or  crown.  The  differ- 
ence between  the  8  and  12  inch  walls  should  be  upon  the 
outside,  and  a  single  course  of  brick  placed  obliquely  for 
the  shedding  of  rain  and  melting  snow.  By  this  means  the 
interior  of  the  kiin  has  a  smooth  surface,  which  should  in 
all  cases  be  closely  pointed  in  its  joints  and  free  from  any 
loose  material.  For  the  purpose  of  filling  and  emptying, 


HAND-BOOK   FOR   CHARCOAL    BURNERS.  185 

two  arched  doors  are  built,  one  upon  the  floor  level  and  in 
front,  and  the  other  (through  which  the  upper  courses  of 
wood  are  admitted)  at  an  elevation  of  12  feet  and  in  the 
rear.  In  all  cases  the  wood  should  be  uniformly  piled  and 
free  from  looseness. 

In  the  centre  is  placed  the  material  with  which  to  put 
the  kiln  in  operation,  access  to  which  is  gained  by  leaving 
a  small  space  from  the  centre  to  the  front,  through  which 
lire  may  be  introduced,  after  which  this  space  is  filled 
with  wood,  and  the  door  closed  and  cemented  to  admit  of 
no  air  while  the  process  of  coaling  is  going  on.  By  means 
of  the  vents  described  above,  the  fire  can  be  drawn  to  any 
portion  of  the  interior  desired  by  the  collier,  who  is  always 
careful  to  keep  them  sufficiently  open  to  permit  without 
obstructing  the  escape  of  all  smoke,  etc.,  which  are  liber- 
ated during  the  period  of  charring.  When  the  wood  is 
sufficiently  charred,  these  vents  are  closed  and  the  fire  al- 
lowed to  die  out,  usually  occupying  from  three  to  four  days 
to  accomplish  it ;  after  which  the  lower  door  is  taken  out 
and  the  coal  taken  from  the  kiln. 

The  kiln  above  described  is  of  the  Bee  Hive  pattern  or 
form,  and  is  made  of  various  capacities,  but  rarely  exceed- 
ing 50  nor  less  than  25  cords. 

Mr.  White  claims  that  it  will  yield  from  38  to  40 
bushels  of  charcoal  to  the  cord  of  wood  employed,  and  be 
free  from  brands.  In  Berkshire,  Massachusetts,  with  kilns 
of  a  capacity  of  60  cords  each,  the  product  has  been  50 
bushels  to  the  cord.  It  is  there  estimated  that  the  cost  of 
coaling  is  less  than  one-half  that  of  coaling  in  pits  when 


186  HAND-BOOK    FOR    CHARCOAL    BURNERS. 

the  wood  is  delivered.  At  Bennington,  Vermont,  with 
kilns  of  a  capacity  of  50  cords  of  wood,  the  product  was 
55  to  60  bushels  to  the  cord. 

Rectangular  piles,  holding  30  to  40  cords  each,  are 
common  upon  the  shores  of  the  Chesapeake.  They  are 
supplied  with  pine  from  the  forests  around  the  hay. 

In  the  Lake  Superior  region,  both  circular  and  rect- 
angular kilns  are  common,  usually  made  of  brick,  but 
sometimes  of  stone.  In  the  rectangular  kilns  the  length 
is  from  two  to  three  times  the  breadth. 

NOTE   VI. 

PERCY'S  Metallurgy  gives  two  methods  of  making 
wood-charcoal  practised  in  China.  When  the  soil  is 
sandy,  charring  is  effected  in  pits ;  and  when,  on  the  con- 
trary, it  is  clayey,  and  the  locality  is  suitable,  arched 
chambers  are  excavated,  in  which  the  wood  is  carbonized. 
The  last  method  is  preferred  by  the  Chinese,  who  have 
carried  it  to  such  a  degree  of  perfection  that  all  the 
small  branches  and  twigs  are  carbonized  without  losing 
their  form. 

The  First  Method. — The  pits  are  circular,  and  are  never 
deeper  than  6  feet,  but  they  sometimes  exceed  14  feet  in 
diameter.  The  chimney  is  round,  and  the  base  is  from  8 
inches  to  14  inches  below  the  bottom  of  the  pit ;  it  rises 
about  3  feet  3J  inches  above  the  ground,  and  is  connected 
with  the  pit  by  an  oblong  opening  not  exceeding  14 
inches  in  length,  and  from  2  inches  to  4  inches  in  depth ; 
the  dimensions  of  this  opening  depend  upon  the  quantity 


HAND-BOOK   FOE    CHARCOAL    BURNERS.  187 

arid  the  size  of  the  wood  to  be  charred.  In  pits  14  feet 
in  diameter,  the  chimney  at  the  base  is  14  inches  in  width, 
and  narrows  upward  to  7  inches  in  width.  In  that  part 
of  the  pit  which  is  opposite  the  chimney  is  an  inclined 
conical  channel,  from  the  lower  end  of  which  a  vertical 
cylindrical  chimney,  4  inches  in  diameter,  rises  to  the  sur- 
face. The  axis  of  the  conical  channel  ought  to  have  such 
an  inclination  that  its  lower  or  narrow  end  is  about  equi- 
distant from  the  bottom  and  upper  edge  of  the  pit.  The 
bottom  of  the  pit  is  covered  with  a  bed  of  dry  branches, 
upon  which  the  wood  is  piled  vertically,  taking  care,  as 
usual,  to  leave  as  little  interstitial  space  as  practicable. 
When  the  pit  is  filled,  the  wood  is  covered  first  with  small 
branches  and  then  with  a  layer  of  soil  sufficiently  thick 
to  be  impervious  to  smoke.  The  wood  is  lighted  through 
an  opening  opposite  the  chimney,  which  is  left  open ;  but 
occasionally  ignition  is  facilitated  by  making  a  small  hole 
above,  at  about  10  inches  from  the  chimney,  and  closing 
it  as  soon  as  smoke  begins  to  escape.  If  the  smoke  is 
copious,  the  pit  is  covered  with  stones,  a  small  opening 
only  being  left  to  promote  combustion.  Five  days  after 
lighting,  the  smoke  begins  to  get  purer  ;  and  when  it  has 
become  quite  transparent,  the  pit  and  chimney  must  be 
hermetically  closed.  Five  or  six  days  suffice  for  the  com- 
plete extinction  of  the  charcoal,  after  which  the  pit  may 
be  opened.  Experience  in  China-  has  shown  that  the 
more  freshly  the  wood  is  cut,  the  less  is  the  loss :  100 
pounds  of  freshly-cut  wood  are  stated  to  yield  from  30  to 
35  of  charcoal,  which,  judging  from  experience  in  Europe, 


188  HAND-BOOK    FOR    CHARCOAL    BURNERS. 

cannot  be  correct  if  black  charcoal  of  good  quality  is  pro- 
duced. When  a  large  quantity  of  wood  is  to  be  charred, 
the  pits  are  made  wider,  but  not  deeper. 

The  Second  Method. — The  arched  chamber,  excavated 
in  the  clayey  ground,  is  4  feet  8  inches  high  and  14  feet 
wide.  A  lateral  chimney  is  formed  just  as  in  the  first 
method.  In  the  side  of  the  chamber  opposite  the  chimney 
there  is  a  conical  channel  of  which  the  base  is  directed  to- 
ward the  chamber  and  extends  nearly  to  the  arch,  while 
the  top  is  about  intermediate  between  the  bottom  and  the 
arch  above.  The  chamber  is  entered  by  a  low  door,  which 
is  closed  with  stones  as  soon  as  the  charging  is  completed. 
The  wood  is  placed  horizontally,  with  the  usual  pre- 
cautions as  to  interstitial  space.  Ignition  is  effected 
through  the  channel  opposite  the  chimney  ;  and  when  the 
smoke  begins  to  issue  from  the  channel,  it  is  closed  with 
stones,  a  very  small  opening  only  being  left  for  the  pas- 
sage of  the  air.  At  the  end  of  the  charring,  the  same 
course  is  followed  as  in  the  first  method. 

When  a  judgment  respecting  the  stage  of  the  process 
cannot  be  formed  from  an  examination  of  the  smoke,  one 
or  two  freshly-cut  sticks  of  the  size  of  the  finger  are  placed 
across  the  chimney ;  and  when  these  sticks,  impregnated 
with  oil,  become  dry  and  their  fracture  black,  it  is  a  certain 
proof  that  carbonization  is  ended. 


HAND-BOOK    FOR   CHARCOAL   BURNERS. 


189 


NOTE   VII. 

Charring  in  Circular  Piles.* 

Dry  level  ground,  well  sheltered  from  the  wind,  and,  if 
possible,  near  a  water-supply,  should  be  chosen  for  the  site. 
The  bed  on  which  the  pile  rests  should  have  a  slight 
inclination  upwards,  from  the  circumference  to  the  centre. 
In  the  centre  three  stakes  (&,  Fig.  39)  are  driven  in  verti- 
cally about  a  foot  equidistant  from  each  other,  and  are 
prevented  from  yielding  to  pressure  from  without  by 
means  of  pieces  of  wood  placed  crosswise  from  stake  to 


Fig.  39.  Vertical  section  through  the  centre  of  a  pile.  At  the  foot  on 
the  left  the  cover  is  shown  resting  on  stones,  and  on  the  right  it  is 
shown  resting  on  branches  supported  by  forked  sticks.  Copied  from 
No.  301  of  Karsten's  Atlas. 

stake,  or  by  suspending  a  single  block  of  wood  between 
them.     Pieces  or  logs  of  wood  of  equal  length  are  piled 

*  Percy's  Metallurgy. 


190  HAND-BOOK   FOR   CHARCOAL    BURNERS. 

concentrically  around  the  stakes,  placing  those  nearest  the 
centre  almost  vertical,  and  giving  the  surrounding  pieces 
a  slight  but  gradually  increasing  inclination.  A  second 
layer  of  wood,  and  in  the  case  of  very  large  piles  even  a 
third,  may  be  stacked  in  a  similar  manner,  one  above  an- 
other. The  wood  should  be  packed  as  close  as  possible  ; 
and  all  large  interstices,  due  to  irregularity  of  shape  in 
the  pieces,  should  be  filled  with  the  small  wood  of  branches. 
The  top  of  the  pile  is  covered  with  a  layer  of  the  same 
kind  of  small  wood,  placed  horizontally  and  radially,  so 
that  the  whole  pile  may  have  the  form  of  a  truncated 
cone,  rounded  at  its  upper  and  smaller  end.  Close  to  and 
round  the  base  of  the  pile,  a  row  of  forked  sticks  is  driven 
into  the  ground,  with  the  forked  ends  uppermost  and 
about  six  inches  out  of  the  ground.  The  pile  is  then  en- 
circled with  a  band  of  branches,  resting  in  the  forks  of 
these  sticks.  This  band  supports  the  cover  of  the  pile 
which  has  next  to  be  applied.  A  row  of  stones  or  pieces 
of  wood  placed  at  intervals  may  be  used  instead  of  forked 
sticks.  The  surface  of  the  pile  is  made  more  or  less  even 
by  packing  in  here  and  there  bits  of  wood  or  small  branches. 
The  whole  pile  above  the  band  of  branches,  except  the 
space  between  the  tops  of  the  three  central  stakes,  is  now 
covered  with  turf,  placing  the  grassy  side  inwards  ;  and 
if  turf  cannot  be  got,  leaves  or  .moss  may  be  substituted. 
The  turf  is  plastered  over  with  a  layer  some  inches  thick 
of  the  soil  which  may  be  at  hand,  or,  when  procurable, 
with  a  mixture  of  the  residual  charcoal  dust,  or  breeze,  of 
previous  burnings  and  soil,  moistened  sufficiently  with 


HAND-BOOK   FOR    CHARCOAL    BURNERS.  191 

water  As  a  rule,  the  cover  should  be  most  solid  and 
thickest  at  the  top  of  the  pile,  where  it  is  longest  and 
most  exposed  to  the  action  of  heat. 

The  pile  is  now  ready  for  lighting.  It  is  desirable  that 
this  should  be  done  early  in  the  morning,  and  during  fine 
weather,  because  at  first  much  attention  is  required  on  the 
part  of  the  charcoal-burner ;  and  because  it  is  important 
that  the  pile  should  be  well  and  regularly  kindled,  a  con- 
dition which  cannot  be  ensured  in  bad  weather.  The 
space  within  the  three  central  stakes,  or  chimney,  is  filled 
with  easily  inflammable  wood,  which  is  then  ignited,  and 
the  fire  is  kept  up  by  a  supply  of  fresh  wood  or  charcoal, 
until  the  centre  of  the  pile  has  become  thoroughly  kindled. 
Any  sinkings-in  which  may  occur  at  the  top  of  the  pile 
must  be  made  good  by  taking  off  the  cover  from  that  part 
and  putting  in  fresh  wood.  The  chimney  is  afterwards 
well  filled  with  small  dry  wood  or  charcoal,  and  effectually 
stopped  by  extending  the  turf  and  soil-covering  over  it, 
and  pressing  it  well  down.  In  this,  the  first  or  sweating 
stage  of  the  process,  much  water  condenses  on  the  inner 
surface  of  the  cover,  and  especially  round  the  base  or  foot 
of  the  pile,  which  is  left  uncovered  below  the  band  of 
branches ;  during  this  stage,  without  proper  attention  on 
the  part  of  the  charcoal-burner,  explosions  are  apt  to 
occur,  occasioned,  it  is  said,  by  the  ignition  of  explosive 
mixtures  of  atmospheric  air  and  the  inflammable  gaseous 
products  of  carbonization.  In  support  of  this  statement 
it  is  alleged  that  explosions  never  occur  wThen  much  steam 
escapes  from  the  cover,  and  that  they  very  frequently 


192  HAND-BOOK  FOR   CHARCOAL    BURNERS. 

occur  when  dry  and  resinous  wood  is  used.  Karsten, 
however,  attributes  these  explosions  to  the  sudden  escape 
of  steam. 

When  the  sweating  stage  is  over,  the  covering  of  the 
pile  is  extended  to  the  previously  uncovered  zone  round 
the  base,  and  any  hollows  which  may  be  found  by  probing 
with  a  pole  are  filled  up.  The  cover  in  every  part  is  made 
solid  and  impervious  to  air,  and  the  pile  is  left  to  itself 
during  three  or  four  days,  the  heat  existing  in  its  centre 
being  sufficient  to  effect  the  carbonization  of  much  of  the 
surrounding  wood.  If  left  too  long  in  this  state,  the  fire 
would  be  extinguished ;  to  prevent  which  holes  or  vents 
are  made  in  the  cover  round  the  pile,  on  a  level  with  the 
top  of  the  bottom  layer  of  wood  (Fig.  39).  Thick  yel- 
lowish gray  smoke  at  first  escapes  from  these  vents,  but 
after  a  time  it  becomes  bluish  and  nearly  transparent. 
These  vents  are  then  stopped,  and  another  row  of  them  is 
made  underneath,  when  the  same  change  in  the  appear- 
ance of  the  smoke  ensues.  The  character  of  the  smoke 
indicates  exactly  the  degree  of  carbonization  in  that  part 
of  the  pile  from  which  it  issues.  If  necessary,  after  the 
stopping  of  the  second  row  of  vents,  a  third  may  be  opened 
about  nine  inches  or  so  below.  These  vents  serve  for 
the  escape  of  the  volatile  products  of  the  carbonization, 
and  not  for  the  admission  of  air,  which  enters  chiefly  by 
openings  made  round  the  base  of  the  pile.  When  only 
bluish  transparent  smoke  proceeds  from  the  lowest  vents, 
every  part  of  the  surface  of  the  pile  must  be  well  covered 
and  rendered  as  impervious  to  air  as  practicable. 


HAND-BOOK    FOR    CHARCOAL   BURNERS.  193 

The  pile  is  now  left  at  rest  during  a  few  days,  after 
which  the  charcoal  may  be  drawn  out,  beginning  on  one 
side,  at  the  bottom,  and  from  this  point  proceeding  all 
round,  care  being  taken  to  cover  up  the  pile  as  the  char- 
coal is  withdrawn,  and  to  quench  the  latter  with  water. 
If  water  cannot  be  had,  the  charcoal  must  be  covered  with 
the  dust  of  previous  burnings,  or  with  dry  soil.  If  the 
pile  were  left  to  itself,  it  would  in  time  be  perfectly  ex- 
tinguished ;  but  experience,  it  is  slated,  has  shown  that 
the  charcoal  in  that  case  would  be  less  serviceable  than 
such  as  has  been  rapidly  extinguished — as,  for  example, 
by  water. 

The  position  of  the  vents  may  be  varied  according  to 
circumstances.  The  object  of  the  charcoal-burner  should 
be  to  conduct  the  combustion  as  uniformly  as  possible 
from  the  top  towards  the  bottom,  and  from  the  centre  to- 
wards the  circumference  of  the  pile.  By  making  a  vent 
in  any  part  of  the  pile,  he  has  the  power  of  establishing  a 
current  of  air  through,  and,  consequently,  of  increasing 
the  combustion  in,  that  part.  During  the  process  of  car- 
bonization, wood  usually  decreases  considerably  in  volume, 
so  that  the  degree  of  regularity  in  the  contraction  of  a 
pile  during  the  progress  of  burning  is  a  measure  of  the 
regularity  with  which  the  process  has  been  conducted. 
The  cover,  being  yielding,  adapts  itself  to  the  gradually 
decreasing  size  of  the  pile. 

The  method  of  charcoal-burning  just  described  is  of 
ancient  date,  and  continues  to  be  extensively  practised  ; 

and  in  respect  to  yield  and   quality  of  charcoal,  it  is  not, 
9 


194:  HAND-BOOK   FOR   CHARCOAL   BURNERS.- 

when  properly  conducted,  surpassed  by  any  other.  It  has 
the  advantage  of  not  requiring  any  permanent  construc- 
tion, so  that  the  wood  may  be  burned  on  the  spot  where 
it  is  cut  down,  and  thus  the  expense  of  carriage  to  a  dis- 
tance may  be  greatly  diminished,  as  the  wood  weighs 
about  five  times  as  much  as  the  charcoal  produced.  It 
may  be  modified  in  details  according  to  local  circum- 
stances, and  the  traditional  practice  of  .  the  charcoal- 
burner. 

The  left-hand  side  of  Fig.  40  represents  a  vertical  sec- 


Fig.  40.  Vertical  sections  through  the  centre  of  two  kinds  of  circular 
piles ;  in  one  of  which  the  wood  is  stacked  vertically,  and  in  the  oth«r 
horizontally.  Copied  from  Nos.  300  and  302  of  Karsten's  Atlas. 

tic  n  of  half  a  pile,  similar  to  that  shown  in  Fig.  39,  but 
wilh  a  different  method  of  supporting  the  cover,  namely, 
by  boards  placed  horizontally  round  the  pile,  resting  on 
wooden  props,  a.  The  right  hand  side  of  Fig.  40  is  a  ver- 
tical section  of  the  half  of  another  kind  of  pile  described 
further  on. 


HAND-BOOK  FOR  CHARCOAL  BURNERS.  193 

FIRST  MODIFICATION  OF  CHARRING  IN  CIRCULAR  PILES. — • 
The  three  central  stakes  may  be  replaced  by  one  (c,  Fig. 
40) ;  but  in  this  case  it  is  necessary  to  construct  a  channel 
from  the  outside  to  the  centre  of  the  base  of  the  pile,  by 
means  of  which  burning  fuel  may  be  introduced  so  as  to 
ignite  the  wood  at  the  bottom  of  the  central  stake,  imme- 
diately around  which  easily  combustible  matter  should  be 
placed.  For  this  purpose  imperfectly  charred  wood  from 
a  previous  charring  may  be  used.  When  the  pile  is  well 


Fig1.  41.  Plan  of  a  circular  pile  at  Ruhpolding  in  Bavaria.     Copied 
from  Plate  2  of  Klein's  Treatise. 


kindled,  the  outer  end  of  the  channel  must  be  closed.  The 
channel  may  be  made  either  by  leaving  a  space  between 
the  logs  at  the  bottom  or  by  making  a  furrow  in  the  bed 
of  the  pile.  Pieces  of  wood  may  be  placed  upon  the  bed, 
radiating  from  the  centre  as  in  Fig.  41,  and  the  channel 
formed  by  two  parallel  pieces  as  at  a ;  pieces  of  wood 
are  next  arranged  concentrically,  as  shown  in  one-half  of 


196  HAND-BOOK    FOR   CHARCOAL    BURNERS. 

the  same  figure,  and  so  a  firm  foundation  of  wood  is  made 
for  the  pile.  The  channel  may,  however,  be  omitted, 
and  a  central  stake  fixed,  extending  upwards  abont  one- 
third  of  the  height  of  the  pile,  a  hollow  space  being  left 
above  the  stake  for  the  purpose  of  igniting  in  the  manner 
first  described.  The  outer  dark  ring  in  Fig.  41  represents 
charcoal-dust  or  breeze  covering  the  bed  of  the  pile. 

Fig.  42  is  a  vertical  section  of  a  pile  through  the  centre. 
Around  the  central  stake,  #,  is  packed  easily  inflammable 
wood,  such  as  the  imperfectly  carbonized  pieces  termed 
brands  from  a  previous  charring.  The  lower  part  of  the 
cover  is  supported  by  stakes,  c  :  in  the  middle  of  each  of 
these  stakes  is  fixed,  at  right  angles,  a  board,  d.  Besting 
upon  the  tops  of  the  stakes,  c,  are  boards,  e,  extending 
round  the  pile.  These  boards  support  the  cover  from  e  to 
f.  The  upper  part  of  the  pile  is  propped  all  round  by 


Fig.  42.  Vertical  section  through  the  centre  of  a  circular  pile  at  Ruh- 
polding  in  Bavaria.     Copied  from  Plate  2  of  Klein's  Treatise. 

poles,  on  the  top  of  each  of  which  is  fixed  a  cross-piece, 
as  shown  at,/,  Fig.  42,  and  in  Fig.  43,  in  which  one  is  seen 
lying  in  the  foreground  to  the  left.  The  pile  is  left  un- 
covered round  the  zone,  r/,  for  some  time  after  ignition. 


HAND-BOOK  FOK  CHARCOAL  BURNERS.  197 

Fig.  43  represents  a  pile  of  this  kind,  of  which  the  height 
is  16  feet :  the  man  on  the  plank  is  engaged  in  carrying  np 
the  breeze  with  which  to  complete  the  cover  at  the  top  ; 


Fig.  43.  Charcoal-burning1  at  Ruhpolding  in  Bavaria. 

in  the  left  foreground  are  various  implements  used  by  the 
charcoal-burner  ;  the  scene  is  Ruhpolding,  in  Bavaria,  and 
the  artist  is  Mr.  Justyne,  who,  with  the  exception  of  the 
picturesque  group  of  figures,  has  derived  the  materials  of 
his  drawing  from  the  plates  in  the  work  of  Klein. 

SECOND  MODIFICATION  OF  CHARRING  IN  CIRCULAR  PILES. 
— The  wood  is  piled  horizontally  and   radially  in   con- 


198  HAND-BOOK    FOR    CHARCOAL    BURNERS. 

centric  rows.  The  spaces  between  the  pieces  will  be 
wider  towards  the  outside  than  the  centre,  and  these  must 
be  well  packed  with  small  wood.  By  sawing  the  wood  to 
suitable  lengths,  the  pieces  may  be  so  piled  as  to  form  a 
series  of  steps  round  the  outside  of  the  pile,  which  will 
tend  to  prevent  the  cover  from  slipping  off.  By  this 
means  of  supporting  the  cover,  the  pile  may  be  made  much 
steeper,  a  condition  favorable  to  complete  carbonization 
of  the  whole  mass.  The  outer  ends  of  the  pieces  upon 
which  the  cover  rests  are  less  coaled  in  steep  piles  than  in 
flat  ones. 

THIRD  MODIFICATION  OF  CHARRING  IN  CIRCULAR  PILES. 
— The  pieces  are  piled  at  first  vertically  round  the  axis  for 
some  distance,  and  then  horizontally,  as  shown  at  1)  on  the 
right-hand  side  of  Fig.  40.  In  this  arrangement  Karsten 
remarks  that  the  hollow  spaces  are  reduced  to  a  minimum ; 
and  with  pieces  of  equal  length  in  the  outer  part  of  the 
pile  steps  are  formed,  as  in  the  last  case,  by  which  the 
cover  is  firmly  supported.  It  is  especially  necessary,  in  a 
pile  of  this  kind,  according  to  Karsten,  to  cover  the  bed 
with  a  layer  of  waste  pieces  of  wood,  in  order  that  the 
charring  may  extend  well  to  the  bottom. 

There  has  been  much  discussion  whether  it  is  most  ad- 
vantageous to  stack  the  wood  vertically  or  horizontally, 
and  practical  charcoal-burners  are  still  far  from  unani- 
mous on  the  subject.  Experimental  results  have  been 
advanced  in  favor  of  each  method  of  stacking. 

FOURTH  MODIFICATION  OF  CHARRING  IN  CIRCULAR  PILES. 
—  A  conical  cavity,  lined  with  brick,  1-33  metre  (4  ft.  4J 


HAND-BOOK    FOR    CHARCOAL    BURNERS.  199 

in.)  in  diameter  at  the  top,  0*5  metre  (1  ft.  7f-  in.)  at  the 
bottom,  and  0*5  metre  (1  ft.  7f  in.)  deep,  is  made  in  the 
centre  of  the  bed.  Three  rectangular  brick  fines  0-12 
metre  (4f  in.)  on  the  side  proceed  from  the  bottom  of 
this  cavity,  and  communicate  with  the  external  air  beyond 
the  base  of  the  pile.  The  cavity  is  filled  with  small  wood 
and  imperfectly  charred  piec.es,  and  then  covered  with 
sheet  iron.  The  construction  generally  resembles  that 
which  is  described  by  Karsten,  and  represented  in  Fig.  44 
The  diameter  of  the  pile  at  the  base  is  9  metres  (29  ft.  6J- 
in.) ;  the  wood  is  sawn  in  lengths  of  O67  metre  (2  ft.  2£ 
in.),  and  piled  vertically  in  three  layers  one  above  another. 
In  every  part  immediately  over  the  cavity  underneath,  a 
thick  layer  of  soil  and  small  charcoal  is  put  upon  the  first 
layer  of  wood,  but  in  other  respects  the  pile  is  made  in 
the  usual  way,  except  that  no  central  chimney  space,  or 
channel  leading  from  the  circumference  to  the  centre  of 
the  bed,  is  left ;  care  is  taken  to  diminish  the  interstices 
as  much  as  possible,  and  to  stack  each  piece  in  a  diametral 
plane  passing  through  the  axis  of  the  pile.  The  fuel  in 
the  cavity  is  then  ignited.  The  upper  part  of  the  pile  is 
uncovered,  and  holes  are  opened  round  the  base.  When 
the  fuel  is  well  kindled,  the  three  flues  above  mentioned  are 
closed,  the  top  is  covered,  arid  the  process  conducted  as 
usual.  From  28  to  35  cubic  metres  (987  to  1236  cubic 
feet)  of  wood  may  thus  be  carbonized  in  four  or  five  days. 
At .  Audincourt,  where  this  method  is  practised,  it  has 
been  found  better  to  operate  upon  this  quantity  of  wood 
than  upon  150  or  180  cubic  metres  (5298  to  6357  cubic 


200  HAND-BOOK   FOE   CHARCOAL    BURNERS. 

feet)  at  a  time,  as  was  formerly  done.  The  advantage 
claimed  for  this  method  is,  that  it  does  away  with  the  cen- 
tral chimney  space  and  the  necessity  of  repeatedly  charg- 
ing that  space  with  fresh  wood  during  some  time  after 
lighting ;  but  it  is  not  adapted  to  charcoal-burning  in 
forests,  where  the  site  of  the  pile  is  constantly  changed  ; 
nor  can  it  well  be  employed  in  very  moist  soils,  on  ac- 
count of  the  difficulty  of  kindling  the  wood  in  the  cavity. 
Another  advantage  in  these  small  piles  is  that  the  char- 
coal-burner can  more  easily  manage  them  than  large 
ones. 

FIFTH  MODIFICATION  OF  CHARRING  IN  CIRCULAR  PILES, 
WITH  AN  ARRANGEMENT  FOR  COLLECTING  TAR  AND  PYRO- 
LIGNEOUS  ACID. — This  method,  like  the  last,  is  only  suit- 
able when  charring  can  be  continuously  and  profitably 
conducted  at  one  spot.  Fig.  44  represents  a  vertical  sec- 
tion through  the  centre  of  such  a  permanent  bed  of  brick- 


Fig1.  44.   Vertical  section  through  the  centre  of  a  permanent  bed  of  a 
circular  pile.     Copied  from  No.  297  of  Karsten's  Atlas. 


work,  «,  which  slopes  towards  the  centre  downwards,  and 
not  downwards  from  it  as  in  the  ordinary  pile.  In  the 
centre  of  the  bed  there  is  a  cylindrical  cavity,  from  which 
proceeds  a  channel,  b,  to  a  reservoir,  c,  provided  with  a 


HAND-BOOK   FOR   CHARCOAL    BURNERS.  201 

movable  cover,  g,  such  as  a  plate  of  iron  ;  the  cylindrical 
cavity  is  covered  with  a  square  plate  of  iron,  d,  of  which 
the  corners  are  rounded  off.  The  tar  and  other  liquid 
products  condense  and  trickle  down  between  the  sides  of 
the  plate,  d,  and  the  brickwork,  and  flow  into  the  reser- 
voir, c.  The  wood  is  stacked  up  in  the  usual  way.  Care 
must  be  taken  to  prevent  access  of  air  through  the  chan- 
nel, 5. 

NOTE   VIII. 

Tables  giving  the  results  of  experiments* 

1.  Showing  the  percentage  composition  of  wood  char- 
coal according  to  Faisst. 

I.  II.  III. 

Carbon 85-89  ....  85-18  ....  8743 

Hydrogen 2-41  ....  2'88 .. . . .  2-26 

Oxygen  and  nitrogen.. .     1*45  ....  3*44  ....  0*54 

Ash 3-02 2-46....  1*56 

Water I 7'23  ....  6-04  ....  8-21 

100-00          100-00         100-00 


I.  Beech  wood  charcoal  from  piles.  II.  Hard  charcoal 
from  wood  vinegar- works.  III.  Light  charcoal  from  wood 
gas-works. 

*  Percy's  Metallurgy,  p.  354. 


202 


HAND-BOOK    FOR   CHARCOAL    BURNERS. 


2.  Showing  the  percentage  composition  of  charcoal  pre- 
pared at  different  temperatures  from  wood  previously 
dried  at  150°  C.,  according  to  Yiolette. 


Temperature      in 

Composition  of  Charcoal  produced. 

Centigrade     De 

No. 

grees    at    which 
Carboni  z  n  t  i  o  n 
was  effected. 

Carbon. 

Hydro- 
gen. 

Oxygen, 
Nitrogen 
and  Loss. 

Ash. 

Observations. 

I. 

ISO- 

47-51 

6-12 

4(5*29 

0-08  » 

(  The   products  obtained  at  these 

II. 
III. 

SOU0 
2(0° 

51-82 
70-45 

3-99 
4-64 

43-97 
24  -OH 

0-22  f 
0-85 

-v      temperatures  ran  not  properly 
(     be  termed  charcoal. 

IV. 

350° 

7H(>I 

414 

18-(il 

0-61 

V. 

432* 

81-64 

1-% 

15*24 

1-16 

Melting-point  of   antimony. 

VI. 

1023° 

81-97 

2-30 

14-13 

1-60 

do.                silver. 

VII. 

1100° 

8^-29 

1-70 

13.711 

1-22 

do.                copper. 

VIII. 

1250° 

88-14 

1-41 

925 

1"20 

do.                gold. 

IX. 

1300° 

90-81 

1-58 

6-46 

115 

do.                steel. 

X. 

1500° 

94-57 

0-74 

4-03 

0'6B 

do.               iron. 

XI. 

Beyond  1500° 

96-51 

0'62 

0-93 

194 

do.                platinum, 

The  wood  operated  on  was  that  of  black  alder  or  alder 
buckthorn  (Rliymnus  Frangula,  L.),  which  furnishes  a 
charcoal  suitable  for  gunpowder. 

3.  Showing  the  nature  and  proportions  of  the  fixed  and 
volatile  matter  produced  by  the  carbonization  of  wood 
(previously  dried  at  150°  C.)  at  different  temperatures, 
according  to  Violette.  (For  Table,  see  next  page.) 

The  wood  experimented  upon  was  that  of  black  alder 
or  alder  buckthorn  (Rliamnus  Frangula^  L.) ;  the  hori- 
zontal line  No.  1  gives  its  composition  when  dried  at  150° 
C.  In  order  to  show  the  use  of  this  table,  suppose,  for  the 
sake  of  example,  that  a  question  should  be  asked  concern- 
ing the  effect  of  carbonizing  wood  at  432°  C.  The  answer 


HAND-BOOK   FOR    CHARCOAL    BURNERS. 


203 


will  be  found  in  the  horizontal  line  No.  Y.,  and  is  as  fol- 
lows :-The  weight  of  the  charcoal  is  15.40  +  3.25  +  0.22  = 
18.87  per  cent,  of  the  dry  wood  ;  and  the  charcoal  consists 
of  15.40  of  carbon.  3.25  of  oxygen,  hydrogen,  and  nitro- 
gen, and  0.22  of  ash.  In  producing  that  weight  of  char- 
coal from  100  parts  by  weight  of  dry  wood,  the  matter  vol- 


No. 

I. 
II. 
III. 
IV. 
V. 
VI. 
VII. 
VIII. 
IX. 
X. 
XI. 

Temperature 
in  Centigrade 
Degrees  at  which 
Carbonization 
was  elfected. 

150° 
200° 
270° 
350° 
482° 
1028° 
1100° 
1250° 
IfcOtt" 
1500° 
Beyond  1500° 

Products  of  the  Decomposition  of  100  parts  by 
weight  of  Wood  by  Carbonization  at  different 
Temperatures. 

a 

ii 

13 
fc-l 

! 

JL 

100-00 
100-0(1 
100-00 

100-00 
100-00 

100-04 
100-00 
100-00 
100-00 

100-00 

100-00 

Composition  of  the  Solid 
Matter  or  Charcoal. 

Composition    of   the 
Matter   volatilized. 

Carbon. 

47-51 
39-95 
2tf'17 
22-73 
15-40 
15-37 
15-32 
15-81 
15^6 
16-37 
14-48 

Gaseous 
Elements 
(H,  0,  N). 

52-41 
3697 
10-65 
6-75 
3-25 
3-12 
2-86 
1-91 
1-40 
0-83 
0-23 

Ash. 

Carbon. 

7-56 
21-34 
2478 
32'  11 
3214 
82-19 
31-70 
31-65 
31-14 
33-08 

Gaseous 
Elements 
(H,  0,  N.) 

1534 

41-52 
45-56 
49-02 
4911 

49M1 
50-36 
50-89 
51'55 
51-97 

0-08 
0-18 
0-32 
0-18 
0-22 
026 
0-22 
0-22 
0-20 
Oil 
0-23 

atilized  is  32.11  +  49.02  =  81.13  per  cent,  and  consists  of 
32.11  of  carbon  and  49.02  of  the  gaseous  elements,  hy- 
drogen, oxygen,  and  nitrogen. 

4.  Showing  the  yield  of  wood-charcoal  by  carbonization 
when  the  volatile  products  are  not  allowed  to  escape,  but 
are  retained  under  pressure.  (For  Table,  see  next  page.) 


204 


HAND-BOOK    FOR    CHARCOAL    BURNERS. 


No. 

I. 
II. 
III. 

IV. 
V. 
VI. 
VII. 
VIII. 
IX. 

Temperature  of 
Carbonization  in 
Centigrade  Degrees. 

Yield  by  Weight  of  Charcoal  per  cent,  of 
the  dry  Wood. 

By  Carbonization, 
not 
under  Pressure. 

By  Carbonization, 
under  Pressure, 
in  hermetically 

closed  Vessels. 

160° 
180° 
200° 
220° 
240° 
260° 
280° 
320° 
340° 

98-00 
88-59 
77-10 
67-50 
50-79 
40-23 
86-16 
31-77 
29-66 

97-4 
93-0 

87-7 
86-4 
83-0 
82-5 
83-8 
78-7 
79-1 

5.  Showing .  the  composition  of  wood-charcoal  made  at 
different  temperatures  under  pressure. 


Composition  per  Cent. 

No. 

Carbonization  in  Cen- 
tigrade Degrees. 

Carbon. 

Hydrogen. 

Oxygen, 
Nitrogen, 

Ash. 

and  Loss. 

I. 

160° 

49-02 

5-30 

45-53 

0-15 

II. 

180° 

56-52 

6-19 

37-09 

0-20 

III. 

200° 

61-04 

5-25 

33-42 

029 

IV. 

220° 

66-42 

4-98 

28-01 

0-59 

V. 

240° 

67-13 

5-17 

25  93 

1-77 

VI. 

260° 

67-62 

5-10 

25-20 

2-08 

VII. 

280° 

64-60 

5-42 

26-78 

3-20 

VIII. 

320° 

65-62 

4-76 

25-55 

4-07 

IX. 

340° 

77-07 

4-71 

14-38 

3-84 

At  the  temperature  of  180°  C.  under  pressure,  the  pro- 
duct was  very  brown  (tres-roux),  very  friable,  and  in  phys- 


HAND-BOOK    FOR    CHARCOAL    BURNERS.  205 

ical  properties  exactly  like  the  brown  (r&ux)  charcoal 
which  is  produced  not  under  pressure  at  280°  C. ;  but  in 
chemical  composition  it  differed  greatly  from  the  latter,  of 
which  the  percentage  composition  was  found  to  be  —  car- 
bon, 72.64 — hydrogen,  4.71 — oxygen,  nitrogen,  and  loss, 
22.08— ash,  0.57.  At  the  temperature  of  300°  C.  and  be- 
yond, wood  (according  to  Yiolette,  who  conducted  the  ex- 
periments, the  results  of  which  are  recorded  in  the  last 
two  tables)  fuses,  loses  all  organic  structure,  and  adheres 
strongly  to  the  tube.  When  cold,  it  is  lustrous,  cavernous, 
hard,  brittle,  and  exactly  resembles  caking  coal  (houille 
grasse). 

6.  Showing  the  weight  of  a  cubic  metre  of  charcoal 
from  different  kinds  of  wood  in  the  Ariege,  French  Pyr- 
enees, according  to  Fran 9015. 

Kilogrammes  per 
Cubic  Metre. 

Oak,  black,  25  years  old 2o5 

Beech,  coppice-wood,  cut  after  an  interval  of  19  years. .  229 

Beech,  large,  and  cut  into  billets 218 

Chestnut,  young 192 

Scotch  fir  ?  (Pin),  branch-wood 173 

Silver  fir  mixed  (Sapin  mele)  large  wood  and  branches ...  152 

Alder 141 

In  the  department  of  Ardennes,  in  France,  the  weight 
of  a  cubic  metre  of  charcoal  produced  in  circular  piles 
from  a  mixture  of  the  hard  wood  of  beech,  oak  and  horn- 
beam, and  from  a  mixture  of  the  soft  wood  of  poplar  and 
willow,  is  stated  to  be  220  and  180  kilogrammes,  respec- 
tively. 


206 


HAND -BOOK    FOR    CHARCOAL    BURNERS. 


It  has  been  determined  at  Prussian  iron- works  that  1 
cubic  foot  of  charcoal  from  Scotch  fir  weighs  from  10.3 
to  10.9  pounds  avofrdupois ;  and  that  1  cubic  foot  of  oak 
or  beech  charcoal  weighs  from  13.2  to  14.1  pounds. 

7.  Showing  the  number  of  volumes  of  various  gases 
absorbed  by  one  volume  of  boxwood-charcoal. 


Ammonia 90 

Hydrochloric  acid 85 

Sulphurous  acid 65 

Sulphuretted  hydrogen 55 

Olenant-gas 35 


Carbonic  acid 35 

Carbonic  oxide 9  43 

Oxygen 925 

Nitrogen 7*5 

Hydrogen 1*75 


From  these  data  it  would  appear  that  the  volume  of  gas 
absorbed  is  great  in  proportion  to  the  condensability  of 
the  gas  by  pressure. 

An  investigation  has  been  made  by  Blumtritt  in  the  la- 
boratory of  Professor  Reichardt,  of  Jena,  concerning  the 
nature  and  quantity  of  the  gas  existing  in  various  solid 
substances,  of  which  one  was  wood-charcoal.  The  gas  was 
evolved  by  heating  the  substance  under  mercury  to  140° 
C.  in  a  paraffine  bath,  in  an  apparatus  contrived  by  Reich- 
ardt. In  the  table  on  next  page  are  given  Blnmtritt's 
results  obtained  in  the  case  of  charcoal. 

8.  Showing  the  nature  and  quantity  of  the  gases  exist- 
ing in  wood-charcoal.  (For  Table,"  see  next  page.) 


I.  The  charcoal  was  from  coniferous  wood,  chiefly  silver 
fir,  such  as  is  sold  for  fuel.     Shortly  before  the  experiment 


HAND-BOOK    FOR   CHARCOAL    BURNERS. 


207 


it  was  finely  triturated.     It  is  remarkable  that  the  gas  con- 
sisted wholly  of  nitrogen. 


i^l 

*!§§' 

Percentage   Compo- 

**"* £ 

^  .   (_, 

sition,   by  volume,   of 

fil 

l^l 

the  Gases  evolved. 

1 

Kind  of  Charcoal. 

^11 

^.2  g 

i 

1 

.H 

e 

,0  -g  >>  2 

^3         g 

g 

be    !•£  'o 

-°  'x 

* 

l^-gg 

.1^ 

B 

f  || 

3° 

T 

164-21 

10(1-00 

i 

Tl. 

The  same,   after  having   been   moistened 

and  dried. 

140*11 

59-0 

85-60 

2'12    9-15 

O  .  •(  O 

TTT 

466'95 

198-2 

8350 

IV. 

Ditto          ash  (fraxinus  exceMor)  

413-00 

159-0 

76  -Oh 

1487    911 

V. 

Ditto          alder  (Ainu*  glutinoRO.)  

287-0? 

109-9 

88-27 

54 

(5-31 

VI. 

Ditto          ditto            ditto        in  pieces 

117-67 

78-88 

..      21-12 

The  volume  of  gaa  is  estimated  dry  at  760  millimetres  pressure,  and  at  0°  C. 

II.  The  difference  in  composition  between  the  gas  in 
this  case  and  that  in  the  case  of  I.  is  noteworthy.     Oxi- 
dation of  the  charcoal,  with  the  formation  both  of  car- 
bonic acid  and  carbonic  oxide,  seems  to  have  been  pro- 
moted by  the  presence  of  moisture. 

III.  The  charcoal  had  been  quite  freshly  made  in  a 
covered  crucible  and  finely  triturated.     It  was  found  to 
contain  0.042  per  cent,  of  ammonia,  and  this  was  the  only 
instance  in  which  that  gas  was  detected  in  charcoal. 

IY.  and  Y.  The  charcoal  had  been  made  in  a  covered 
crucible  and  finely  triturated  soon  afterwards. 

YI.  It  will  be  seen  that  charcoal,  in  pieces,  made  from 
alder  contained  less  than  half  of  the  volume  of  gas  exist- 
ing in  the  same  kind  of  charcoal  in  the  state  of  powder, 
yet  an  actually  greater  volume  of  carbonic;  acid. 

Nitric  acid  was  carefully  sought  for  by  Blumtritt  in  his 


208  HAND-BOOK   FOB   CHARCOAL   BURNERS. 

experiments  on  wood-charcoal,  but  not  detected  in  a  single 
instance. 

Blumtritt's  results  differ  widely  so  far  as  they  relate  to 
the  volume  of  gases  absorbed  by  charcoal  from  those  of 
De  Saussure  ;  and  his  method  of  experimenting  also  dif- 
fered much  from  that  of  the  Swiss  chemist,  who  noted  the 
diminution  in  volume  which  the  gases  suffered  by  pro- 
longed contact  with  charcoal,  whilst  Blumtritt  endeavored 
to  ascertain  the  degree  of  absorption  by  measuring  the  gas 
evolved  at  140°  <J. 

9.  Showing  the  composition  per  cent,  by  volume  of  the 
>gases  evolved  from  wood-charcoal  when  strongly  heated, 

I.  II.  III.  IV. 

Carbonic  acid 23'65  ..  1596  ..  19'58  ..  35 '36 

Carbonic  oxide 15 '96  . .  13-62  . .  20 '57  . .  14 '41 

Hydrogen 4939  ..  50'10  ..  39-10  ..  29'45 

Carburetted  hydrogen...    11  "00  ..  20 "32  ..  20*75  ..  2078 


100-00  1-00-00      ..     100-00        .    100-00 


Commercial  charcoal,  even  when  well  burnt,  contains 
a  sensible  amount  of  hydrogen  and  oxygen,  as  Bnnsen  and 
Playfair  have  demonstrated.  They  analyzed  the  gases 
evolved  from  various  specimens  of  charcoal  strongly  heated 
in  close  vessels,  and  found  their  composition  by  volume  to 
be  as  above. 

I.  Very  well-burnt  beeehwood-charcoal. 

II.  Well-burnt  firwood-charcoal. 


HAND-BOOK    FOR    CHARCOAL    BURNERS.  209 

III.  Well-burnt  oak-charcoal,  0.65  gramme,  yielded  70 
cubic  centimetres  of  gas  at  0°  C.  and  760  millimetres  pres- 
sure, and  a  residue  weighing  0.47  gnu. 

IV.  Imperfectly-burnt  beechvvood-charcoal,  pulverulent 
and  of  a  blackish  brown  color,  0.733  gnu.,  yielded  250 
cubic  centimetres  of  gas  at  0°  C.  and  760  millimetres  pres- 
sure, and  a  residue  weighing  0.443  grin. 

For  the  sake  of  comparison  are  here  inserted  the  follow- 
ing results  which  Pettenkofer  obtained  by  carbonizing 
wood  in  boiling  mercury  ;  the  charcoal  so  formed  is  de- 
scribed as  black  and  bright  (schwarze  glanzende  Kohle]  : 
impermanent  gases  produced  were  composed  as  follows, 
exclusive  of  about  5  per  cent,  of  atmospheric  air  : — 

10.  Composition,  per  cent.,  by  volume  of  the  perma- 
nent gases  evolved  by  carbonizing  wood  at  the  temper- 
ature of  boiling  mercury. 

Carbonic  acid 54 '5 

Carbonic  oxide 33'8 

Marsh-gas 6*6 


94-9 


If  the  volatile  products  from  the  carbonization  (under 
the  usual  conditions)  of  wood  be  subjected  to  a  considerably 
higher  degree  of  heat,  a  large  quantity  of  olefiant  gas  is 
generated ;  and  hence  the  successful  application  of  the 
gases  thereby  produced  for  the  purpose  of  illumination. 
Their  composition  has  been  found  to  be  as  follows  : — 


210  HAND-HOOK    FOR   CHARCOAL    BURNERS. 

11.  Composition,  per  cent.,  by  volume  of  the  gases  pro- 
duced by  exposing  the  volatile  products  of  the  carboni- 
zation of  wood  to  a  very  high  temperature. 

Per  cent. 

Carbonic  acid 18  to  25 

Carbonic  oxide 40  to  50 

Hydrogen 14  to  17 

Marsh-gas 8  to  12 

Olefiant-gas 6  to    7 

The  volatile  products,  condensable  as  well  as  perma- 
nently gaseous,  evolved  from  different  kinds  of  wood,  such 
as  beech  and  fir,  have  essentially  the  same  composition. 

Ebelmen  has  determined  the  composition  of  the  gases 
evolved  from  the  charcoal  of  poplar,  and  young  oak,  ob- 
tained by  charring  in  piles.  Both  were  dried  between 
140°  and  150°  C.  The  oak-charcoal  had  been  long  exposed 
to  the  air.  The  poplar-charcoal  lost  5.2  per  cent.,  and  the 
oak-charcoal  6  per  cent,  in  weight  by  desiccation  at  the 
temperature  above  stated.  The  loss  .by  exposure  to  a 
white  heat  in  a  platinum  crucible  was  also  ascertained,  and 
the  results  are  given  in  the  first  table  on  page  211. 

12. 'Showing  the  amount  and  composition  of  the  mat- 
ter evolved  by  subjecting  dry  wood-charcoal  to  a  white 
heat.  (For  Table,  see  page  211.) 

When  steam  is  passed  over  red-hot  charcoal,  hydrogen, 
marsh-gas  in  small  proportion,  carbonic  oxide  and  carbonic; 
acid  are  produced.  Langlois  has  investigated  this  subject, 
and  in  his  experiments  the  charcoal  was  kept  at  a  red  heat 


HAND-BOOK    FOR    CHARCOAL    BURNERS. 


211 


in  a  porelain  tube,  .one  end  of  which  communicated  with 
a  glass  retort  containing  water  for  the  generation  of  steam, 


Poplar. 

Oak. 

Number  of  parts,  by  weight,  of  matter  \ 
evolved   at   a  white   heat   from    100  >• 
parts  by  weight  of  dry  charcoal.          ) 

17-07 

13-06 

Composition  per  cent     (  Carbon. 

301 

28-7 

of   the    matter   so       •<  Hydrogen  
evolved                  f  Oxygen 

18-7 
51-2 

21-6 
49-7 

Total  

lOO'O 

100-0 

and  the  other  with  an  invented  glass  jar  filled  with  mer- 
cury. Much  of  the  gas  formed  at  first  was  allowed  to 
escape,  after  which  seven  jars  of  it  were  collected  and 
separately  analyzed.  The  carbonic  acid  was  absorbed  by 
caustic  potash,  and  the  carbonic  oxide  by  an  ammoiiiacal 
solution  of  dichloride  of  copper,  Cu2Cl  [Cu2Cl2j.  The  re- 
sults are  shown  in  the  following  table  :— 

13.  Showing  the  composition,  per  cent.,  by  volume  of  the 
gases  formed  by  passing  steam  over  incandescent  wood- 
charcoal,  and  collected  in  different  receivers. 


Gas. 

1st  Jar. 

and  Jar. 

3rd  Jar. 

4th  Jar. 

5th  Jar. 

6th  Jar. 

7th  Jar. 

Hydrogen  

59-11 

21-89 
19-OU 

58-64 
26-07 
152:) 

60-55 
20-00 
19-45 

60-48 
20-83 
18-69 

60-18 
21-42 
18-40 

63-37 
19-31 
20-32 

59-86 
20-76 
19-38 

Carbonic  oxide  
Carbonic  acid 

Total  

100-00 

100-00 

100-00 

100-00 

100-00 

100-00 

100-00 

212  HAND-BOOK   FOR   CHARCOAL    BURNERS. 


From  these  results  it  appears  that  the  gases  had  nearly 
always  the  same  composition  at  every  period  of  their  pro- 
duction. The  proportion  of  carbonic  acid,  compared  with 
that  of  carbonic  oxide,  is  much  larger  than  what  is  usual- 
ly observed.  As  this  might  be  due  to  too  low  a  tempera- 
ture, the  experiment  was  repeated  at  a  sustained  red -white 
(rouge-blanc)  heat.  The  composition  of  the  gases  thus 
formed  wras  ascertained  by  the  method  of  analysis  above 
mentioned,  as  well  as  by  explosion  with  oxygen  in  a  eudio- 
meter, and  was  found  to  be  as  follows : — 

14.  Composition,  per  cent.,  by  volume  of  the  gases 
formed  by  passing  steam  over  wood-charcoal  at  a  red- 
white  heat. 

I.  II. 

By  the  1st  By  the  2nd 

method  of  analysis.  method,  of  analysis. 

Hydrogen 52'64  49T>2 

Marsh-gas 2'17 

Carbonic  oxide 41  '36  42'2l 

Carbonic  acid  ..  6  "00  .  G'OO 


100-00  100-00 


Oxygen  consumed 50-25 

Hence,  it  appears  that  at  the  higher  temperature  the  pro- 
portion of  carbonic  oxide  formed  is  much  greater,  and  that 
that  of  the  carbonic  acid  is  proportionately  smaller. 

Another  experiment  was  made  in  order  to  ascertain 
whether  the  composition  of  the  gases  is  influenced  by  the 
quantity  of  charcoal  exposed  to  the  action  of  steam,  and 
for  this  purpose  a  single  piece  of  charcoal  was  operated 


HAND-BOOK    FOR    CHARCOAL    BURNERS.  213 

upon,  of  which  the  dimensions  in  every  direction  scarcely 
exceeded  2  centimetres,  and  the  result  was  found  to  be  as 
follows  by  the  eudiometrical  method  of  analysis  : — 

15.  Composition,  per  cent.,  by  volume  of  the  gases 
formed  by  passing  steam  over  a  single  very  small  piece 
of  wood-charcoal,  at  a  red-white  heat. 

Hydrogen 54 '25 

Marsh  gas 1'74 

Carbonic  oxide 35-37 

Carbonic  acid 8'64 

100-00 


Oxygen  consumed 48-29 

This  experiment,  which  was  repeated  several  times  with 
the  same  result,  would  tend  to  show  that,  supposing  the 
carbon,  which  is  oxidized,  to  be  first  converted  into  car- 
bonic acid,  the  latter  is  for  the  most  part  instantaneously 
reduced  to  carbonic  oxide,  and  that  a  considerable  mass  of 
charcoal  is  not  at  this  temperature  required  to  effect  such 
reduction. 

16.  Showing  the  relative  value  of  French  and  English 
weights  and  measures. 

MEASURES    OF   LENGTH. 

French.  English. 

Millimetre =       0.03937  inches. 

Centimetre  .  ,  .  =  .      0.39371  inches. 


214 


HAND-BOOK    FOR    CHARCOAL    BURNERS. 


French.  English. 

Decimetre —  3.93710  inches. 

Metre =  39.37100  inches. 

Decametre =  32.80916  feet. 

1  lectometre =  328.09167  feet. 

Kilometre =  1093.6389  yards. 

f  10936.38900  yards,  or  6  miles, 

Myriametre =   -J 

(    1  furlong,  28  poles,  2  j-  yards. 

SUPERFICIAL  MEASURES. 
French.  English. 

Milliare =  .1196  square  yards. 

Centiare =  1.1960  square  yards. 

Are  (a  square  decametre)  =       119.6046  square  yards. 

Decare =     1196.0460  square  yards. 

Hectare =  11960.4604  square  yards,  or 

2  acres,  1  rood,  35  perches. 

SOLID    MEASURES. 

French.  English. 

Millistere —        .035317  cubic  feet. 

Centistere —        .35317  cubic  feet. 

Decistre =      3.5317  cubic  feet. 

Stere  (a  cubic  metre) =    35.3171  cubic  feet. 

Decastere =  353.1714  cubic  feet. 

WEIGHTS. 
French.  English. 

Milligramme =  0.0154  grains. 

Centigramme =  0.1544  grains. 


HANU-BOOK   FOR   CHARCOAL    BURNERS. 


215 


French.  English. 

Decigramme. ...  —  1.5444  grains. 

Gramme =         15.4440  grains. 

f  154.4402    grains,   or    5.64    drams 
Decagramme....  =  -j 

(      avoirdupois. 

f  3.2154  oz.  troy,  or  3.527  oz.  avoir- 
liectogramme.. .  =  •< 

(      dupois. 

f  2  Ibs.  8  oz.  3  pwt.  2  gr.  troy,  or  2  Ibs. 

Kilogramme =  \  .  J. '       . 

(      3  oz.  4.4z8  drams  avoirdupois. 

f  26.795    Ibs.    troy,   oc   22.0485    Ibs. 
Myriagramme. . .  =  -j  .  . 

(      avoiraupois. 

Quintal —       1  cwt.  3  qrs.  25  Ibs.,  nearly 

Millier,  or  Bar...  =      9  tons,  10  cwt.  3  qrs.  12  Ibs. 

MEASURES    OF    CAPACITY. 

French.  English. 

Millitre =  0.06103  cubic  inches. 

Centilitre =  0.61028  cubic  inches. 

Decilitre =  6.10280  cubic  inches. 

f  61.02802  cubic  inches,  or 
Litre  (a  cubic  decimetre)  =    4 

{      2.1135  wine  pints. 

(  610.28029  cubic  inches,  or 

Decalitre —    1 

(      2.642  wine  gallons. 

f  3.5317  cubic  feet,  or  2.838 
Hectolitre =    •{       __.     , 

(       Winchester  bushels. 

f  35.3171  cubic  feet,  or  1  tun, 
Kilolitre ==-J  •   •        n 

(      Iz  wine  gallons. 

Myrialitre =        353.17146  cubic  feet. 


216  HAND-BOOK   FOR   CHARCOAL    BURNERS. 

NOTE  IX. 

Charring  in  iron  retorts. 

Coaling  in  iron  retorts  is  earned  on  upon  a  limited  scale 
in  this  country.  Though  the  charcoal  product  is  greater 
than  by  other  methods,  yet  the  expense  is  so  much  greater 
as  to  prevent  its  adoption  where  charcoal  is  the  principal 
object.  This  process  is  used  to  obtain  pyrol igneous  acid, 
wood  naphthavetc. 

NOTE  x. 

Uses  of  Charcoal. 

Charcoal  is  largely  manufactured  as  a  fuel  for  the  reduc- 
tion of  the  metallic  oxides.  For  this  purpose  the  charcoal 
of  the  heavier  woods,  as  oak  and  beech,  is  preferred ;  it 
gives  the  greatest  heat,  but  requires  a  large  supply  of  air 
to  keep  it  burning.  The  charcoal  from  the  lighter  woods 
gives  a  glowing  heat  with  very  little  draught.  Where  a 
steady  and  still  tire  is  required,  charcoal  should  be  used 
made  from  wood  previously  divested  of  its  bark,  since  it 
is  the  bark-coal  which  crackles  and  flies  off  in  sparks 
during  combustion,  while  the  wood-coal  rarely  does. 

The  heating  power  of  charcoal  is  more  than  twice  that 
of  an  equal  weight  of  wood.  According  to  Karsten,  its 
effect,  compared  with  coke  in  iron  blast  furnaces  which 
are  carried  on  with  hot  blast,  is  as  follows : — 

100  parts  in  volume  of  charcoal  =  40  parts  in  volume  of  coke. 
100      "         weight  "        =  125    "        weight          " 


HAND-BOOK   FOR   CHARCOAL    BURNERS.  21 7 

The  following,  when  pig-iron  is  re-melted  in  cupola 
furnaces : — 

100  parts  in  volume  of  charcoal  =  22£  parts  in  volume  of  coke. 
100     "        weight  "        =83i      "         weight          " 

Besides  its  use  as  a  fuel,  charcoal  is  applied  to  many 
other  purposes.  It  is  an  essential  ingredient  in  the  manu- 
facture of  gunpowder ;  that  of  the  willow  or  alder  being 
preferred  for  this.  Iron  is  converted  into  steel  by  cemen- 
tation with  charcoal.  In  medicine,  charcoal  is  used  as  an 
antiseptic  or  absorbent,  being  given  internally,  and  applied 
externally  as  a  dressing  to  wounds  and  ulcers.  Charcoal 
made  from  cocoa-nut  shell  and  bread  is  one  of  the  best 
dentifrices  known. 

To  free  charcoal  from  foreign  ingredients,  as  for  fine 
pigments,  it  may  be  purified  by  digesting  it  in  dilute 
nitric  or  hydrochloric  acid,  and  then  washing  thoroughly 
with  hot  water. 

When  finely  ground,  charcoal  is  used  for  polishing  hard 
substances,  for  lining  crucibles,  for  finishing  the  fine 
smooth  surface  of  moulds  for  nice  castings,  and  for 
making  crayons.  By  the  ancients  it  was  employed  in 
making  an  ink  which,  for  durability,  has  never  been  sur- 


\ 


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